This work was supported by National Natural Science Foundation of China (31371129).

This protocol was approved by the Institutional Review Board of Psychology Department of Sun Yat-Sen University.
NOTE: A custom program &#34;BouncingBall&#34;9 is provided for accomplishing this protocol. Extracting the file &#34;BouncingBall.zip&#34; generates a directory &#34;BouncingBall&#34;, which contains auditory and visual stimuli files (see Section 1 below), a script &#34;BouncingBall_run.m&#34; for programming of stimulus presentation and response recording (see Section 2 below) and presenting stimuli and recording responses (see Section 3 below), and a script &#34;BouncingBall_analyze.m&#34; for programming of data analyses (see Section 4 below) and performing data analyses (see Section 5 below).
1. Preparation of Auditory and Visual Stimuli
NOTE: The &#34;BouncingBall&#34; directory contains generated stimuli. Readers can use or modify the stimuli as required.
<ol>
	<li>Use software in which auditory tones can be generated, to create a pure tone of 600 Hz and 50 ms duration.</li>
	<li>Use software in which visual images can be generated, to create an image of an orange ball with a transparent background.</li>
	<li>Use a smartphone with a camera to take a picture of an orange basketball, and use software in which visual images can be generated, to create an image of the basketball with a black background.</li>
</ol>
2. Programming of Stimulus Presentation and Response Recording
NOTE: The programming of stimulus presentation and response recording is already implemented in the script &#34;BouncingBall_run.m&#34; in the directory &#34;BouncingBall&#34;, which can be opened and edited using a text edit software. Readers can set up or modify the settings as required, following the comments in the script.
<ol>
	<li>Set up the background color as black.</li>
	<li>Set up each sequence to have 55 events (54 IOIs). For practice (see below), set up the event number as 20.</li>
	<li>Set up each sequence to be repeated 6 times. For practice, set up the repetition number as 2.</li>
	<li>Setup the IOI to be 600 ms or 900 ms.</li>
	<li>Construct the AT sequence.
	<ol>
		<li>Present the pure tone every IOI.</li>
		<li>Permanently display an orange ball of 1.74 cm in diameter (subtended a visual angle of 1.66&#176;) and a white bar of 3.54 cm x 4.06 cm. Present the ball at the center of the computer screen and display the bar 0.92 cm below the bottom edge of the ball. 
		NOTE: The orange ball and the bar are presented to keep visual settings as consistent as possible between the AT sequence and the visual sequences, and to keep the subject fixating on the ball and maintaining attention on the auditory task.</li>
	</ol>
	</li>
	<li>Construct the VF sequence.
	<ol>
		<li>Have the orange ball flash every IOI, i.e., it lasts for 50 ms and disappears for the remaining IOI time.</li>
	</ol>
	</li>
	<li>Construct the VB sequence.
	<ol>
		<li>Replace the orange ball with the realistic orange basketball.</li>
		<li>Let the ball continually move 0.92 cm (movement distance) down and touch the white bar, and then move up to the initial position. 
		NOTE: The velocity of the ball is uniformly varied with a constant acceleration. The acceleration is 0.20 m/s2 for the 600-ms IOI or 0.09 m/s2 for the 900-ms IOI. The ball reaches its peak velocity when touching the bar. Use different accelerations for different IOIs.</li>
	</ol>
	</li>
	<li>Record and save the time when the subject presses the responding key on a computer keyboard.</li>
</ol>
3. Experimental Procedure
NOTE: Presenting stimuli and recording responses are accomplished by typing &#34;BouncingBall_run(SequenceType, IOI, ScreenX, ScreenY, isFormal)&#34; in the command window of the software. &#34;ScreenX&#34; and &#34;ScreenY&#34; refer to the width and height of the computer screen in cm, respectively. The tapping data are automatically recorded in the file &#34;SequenceType_IOI_ScreenX_ScreenY.mat&#34; by the program. IsFormal refers to whether the experiment is the formal experiment or the practice.
<ol>
	<li>Ask the subject to sit in front of a computer screen with a 60-cm viewing distance and wear a headset.</li>
	<li>Give the subject the written informed consent form to sign.</li>
	<li>Give the subject the written experiment instructions.
	<ol>
		<li>In the instructions, explain the metronome synchronization task to the subject: tap (on a keyboard key using their index finger of their preferred hand) in synchrony with the tones in the AT sequence, the flashing balls in the VF sequence, and the moments when the bouncing ball moves to the lowest position (i.e., touches the bar) in the VB sequence.</li>
	</ol>
	</li>
	<li>Open the software. 
	NOTE: The software continuously runs and its command window stays open. Typing the Bouncingball_run command in the command window will run the stimulus presentation and return to the command window when the stimulus presentation is finished.</li>
	<li>Ask the subject to practice with the 600 ms IOI AT, VF, and VB sequences twice to become familiar with the stimuli and task. 
	NOTE: The practice was the same as the below formal experiment except: (1) The order of the three sequence types is not changed across the subjects; (2) Each sequence is repeated 2 times; and (3) Each sequence has 20 events.
	<ol>
		<li>Type &#34;Bouncingball_run(&#39;AT&#39;, 600, 53.1, 29.8, 0)&#34; in the command window and then press the &#39;Enter&#39; key, to perform the practice of the AT sequence. 
		NOTE: The screen size was 53.1 cm x 29.8 cm in Gan et al.4, but the readers should assign the size according to the screen that they use. When the experiment program is running, the subject is performing the task described in the experiment instructions. In addition, the sequence presentation is self-paced, i.e., the subject presses the space bar to start a sequence.</li>
		<li>Type &#34;Bouncingball_run(&#39;VF&#39;, 600, 53.1, 29.8, 0)&#34; in the command window and then press the &#39;Enter&#39; key, to perform the practice of the VF sequence.</li>
		<li>Type &#34;Bouncingball_run(&#39;VB&#39;, 600, 53.1, 29.8, 0)&#34; in the command window and then press the &#39;Enter&#39; key, to perform the practice of the VB sequence.</li>
	</ol>
	</li>
	<li>Ask the subject to conduct the experiment. Counterbalance the orders of IOI types and sequence types among subjects. 
	NOTE: Below is the procedure for one subject.
	<ol>
		<li>Type &#34;Bouncingball_run(&#39;AT&#39;, 600, 53.1, 29.8, 1)&#34; in the command window and then press the &#39;Enter&#39; key, to perform the 600-ms IOI AT sequence.
		<ol>
			<li>Note that the subject will tap on a keyboard key using the index finger in synchrony with the tones in the AT sequence.</li>
		</ol>
		</li>
		<li>Type &#34;Bouncingball_run(&#39;VF&#39;, 600, 53.1, 29.8, 1)&#34; in the command window and then press the &#39;Enter&#39; key, to perform the 600-ms IOI VF sequence.
		<ol>
			<li>Note that the subject will tap on a keyboard key using the index finger in synchrony with the flashing balls.</li>
		</ol>
		</li>
		<li>Type &#34;Bouncingball_run(&#39;VB&#39;, 600, 53.1, 29.8, 1)&#34; in the command window and then press the &#39;Enter&#39; key, to perform the 600-ms IOI VB sequence.
		<ol>
			<li>Note that the subject will tap on a keyboard key using the index finger in synchrony with the moments when the bouncing ball moves to the lowest position (i.e., touches the bar).</li>
		</ol>
		</li>
		<li>Type &#34;Bouncingball_run(&#39;AT&#39;, 900, 53.1, 29.8, 1)&#34; in the command window and then press the &#39;Enter&#39; key, to perform the 900-ms IOI AT sequence.
		<ol>
			<li>Note that the subject will tap on a keyboard key using the index finger in synchrony with the tones in the AT sequence.</li>
		</ol>
		</li>
		<li>Type &#34;Bouncingball_run(&#39;VF&#39;, 900, 53.1, 29.8, 1)&#34; in the command window and then press the &#39;Enter&#39; key, to perform the 900-ms IOI VF sequence.
		<ol>
			<li>Note that the subject will tap on a keyboard key using the index finger in synchrony with the flashing balls.</li>
		</ol>
		</li>
		<li>Type &#34;Bouncingball_run(&#39;VB&#39;, 900, 53.1, 29.8, 1)&#34; in the command window and then press the &#39;Enter&#39; key, to perform the 900-ms IOI VB sequence.
		<ol>
			<li>Note that the subject will tap on a keyboard key using the index finger in synchrony with the moments when the bouncing ball moves to the lowest position (i.e., touches the bar).</li>
		</ol>
		</li>
	</ol>
	</li>
</ol>
4. Programming of Data Analyses
NOTE: The programming of data analyses is already implemented in the script &#34;BouncingBall_analyze.m&#34; in the directory &#34;BouncingBall&#34;, which can be opened and edited using a text edit software. Readers can set up or modify the settings as required, following the comments in the script. The raw synchronization data are a sequence of tap times. Use a circular method to analyze the variable periodic synchronization data, which has been detailed in4,5,10. Here, the present protocol describes a procedure to analyze the stability (R) of synchronization, using the circular statistics toolbox (e.g., CircStat toolbox11 ), as described in Gan et al.4
<ol>
	<li>Omit the taps to the first five events in the tap sequence because synchronization typically requires a few taps to stabilize.</li>
	<li>Compute asynchrony.
	<ol>
		<li>For each tap sequence, calculate asynchrony as the difference between the time of a tap and the time of the corresponding event onset, resulting in a sequence of asynchronies. 
		NOTE: It is better to exclude invalid taps for each sequence. Invalid taps include missing tap (i.e., there is no tap during the -1/2 to +1/2 IOI interval around an event) and multiple taps (i.e., when there is more than one tap during the -1/2 to +1/2 IOI interval).</li>
		<li>Convert the times (ms) of asynchronies into angles (degree) by asynchrony*(360/IOI). Then use function circ_ang2rad11 to convert degrees into radians, which results in the relative phase (RP) on a unit circle.</li>
	</ol>
	</li>
	<li>Compute synchronization stability (R).
	<ol>
		<li>For each asynchrony sequence, use function circ_var11 to calculate the variance (S) of the RPs.</li>
		<li>Compute R using R = 1 - S. 
		NOTE: R is the length of the resultant (i.e., average of vectors) of the RPs, ranging from 0 (unstable tapping with uniformly distributed RPs) to 1 (perfectly stable tapping with a unimodal distribution of RPs).</li>
		<li>For each sequence type, calculate the mean value of the RPs of the 6 trials, as the R of that sequence type of that subject.</li>
	</ol>
	</li>
</ol>
5. Performing Data Analyses
NOTE: Below is the analysis of data from one subject collected as introduced above. Performing data analyses is accomplished by typing &#34;Bouncingball_analyze(RecordedFile)&#34; in the command window of the software, which returns the mean and standard deviation (SD) of the stability.
<ol>
	<li>For the 600-ms IOI AT sequence, type &#34;Bouncingball_analyze(&#39;AT_600_53.1, 29.8.mat&#39;)&#34; in the command window and then press the &#39;Enter&#39; key.</li>
	<li>For the 600-ms IOI VF sequence, type &#34;Bouncingball_analyze(&#39;VF_600_53.1, 29.8.mat&#39;)&#34; in the command window and then press the &#39;Enter&#39; key.</li>
	<li>For the 600-ms IOI VB sequence, type &#34;Bouncingball_analyze(&#39;VB_600_53.1, 29.8.mat&#39;)&#34; in the command window and then press the &#39;Enter&#39; key.</li>
	<li>For the 900-ms IOI AT sequence, type &#34;Bouncingball_analyze(&#39;AT_900_53.1, 29.8.mat&#39;)&#34; in the command window and then press the &#39;Enter&#39; key.</li>
	<li>For the 900-ms IOI VF sequence, type &#34;Bouncingball_analyze(&#39;VF_900_53.1, 29.8.mat&#39;)&#34; in the command window and then press the &#39;Enter&#39; key.</li>
	<li>For the 900-ms IOI VB sequence, type &#34;Bouncingball_analyze(&#39;VB_900_53.1, 29.8.mat&#39;)&#34; in the command window and then press the &#39;Enter&#39; key.</li>
</ol>

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L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Compatibility+of+motion+facilitates+visuomotor+synchronization.">Compatibility of motion facilitates visuomotor synchronization.</a> J. Exp. Psychol. Hum. Percept. Perform. 36, 1525-1534 (2010).</li><li>Gan, L., Huang, Y., Zhou, L., Qian, C., Wu, X. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Synchronization+to+a+bouncing+ball+with+a+realistic+motion+trajectory.">Synchronization to a bouncing ball with a realistic motion trajectory.</a> Sci. Rep. 5, 11974 (2015).</li><li>Iversen, J. R., Patel, A. 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The authors have nothing to disclose.

This protocol illustrates how to examine a bouncing ball with a uniformly varying velocity in a metronome synchronization task. Given its comparable synchronization performance to that of auditory tones, the bouncing ball is of particular importance for addressing the current research topic of whether SMS is modality specific. 
The critical step in the current protocol is to introduce the uniformly varying velocity of the bouncing ball, and step-by-step instructions are provided to carry out t...

Sensorimotor synchronization (SMS) refers to the coordination of movements (e.g., finger taps) with an external rhythm, and is canonically studied using a simple metronome synchronization task in which the subject is required to tap a finger along with an isochronous sequence1,2. The superiority of the auditory over visual modality in metronome synchronization has been established for over a century: synchronization is much more stable to an auditory sequence consisting of auditory tones (Figure 1A) than to a visual sequence consisting of visual flashes (Figure 1B)1. This auditory advantage of metronome synchronization, however, has recently been challenged by studies employing periodically moving visual stimuli3,4,5,6 (note that periodically moving visual stimuli refer to continuous movements). Hove et al. used a visual sequence composed of an up-down bar moving with a constant velocity, and found that synchronization of the up-down bar was more stable than synchronization of visual flashes, but was still less stable than synchronization of auditory tones3,6. Iversen et al. employed a bouncing ball that had a velocity varied according to a rectified sinusoid, and showed that synchronization of the bouncing ball was close to synchronization of auditory tones5. More recently, Gan et al. used a bouncing ball that had a uniformly varying velocity (i.e., simulating the effect of gravity) (Figure 1C), and found that synchronization of the bouncing ball was not less stable than synchronization of auditory tones4.
The purpose of the current protocol is to introduce a procedure to apply a bouncing ball with a uniformly varying velocity in a metronome synchronization task, as described in Gan et al.4 The metronome synchronization task includes an auditory sequence composed of auditory tones (AT sequence, Figure 1A) and a visual sequence composed of visual flashes (VF sequence, Figure 1B), which are widely adopted in SMS studies1. The third type of sequence in the task is a visual sequence consisting of the bouncing ball (VB sequence, Figure 1C). Whereas modality-specific mechanisms have long been thought to underlay SMS, such as tighter connections between the auditory and motor cortices than between the visual and motor cortices2, whether SMS is modality specific has recently drawn much research attention1,7. The bouncing ball as introduced in the present protocol is particularly useful for addressing the modality issue because of comparable synchronization performances of the bouncing ball and auditory tones. Moreover, metronome synchronization can be flexibly performed over a limited range of IOI (100-1,800 ms)8. To illustrate the application of the bouncing ball for different IOIs, the current protocol includes a 600-ms IOI (which is approximately the most preferred IOI), and a 900-ms IOI.
<img alt="Figure 1" class="xfigimg" src="/files/ftp_upload/56205/56205fig1.jpg" /> 
Figure 1: Illustration of the stimuli. The subject taps along with an isochronous sequence, which is composed of auditory tones (A: the AT sequence), visual flashing balls (B: the VF sequence), or a visual bouncing ball (C: the VB sequence). In C, the velocity and trajectory of the bouncing ball are plotted as functions of time and are indicated by blue and green lines, respectively. The movement distance of the bouncing ball is 9.2 mm and the peak velocity at the bouncing point (i.e., at the lowest ball position) is 0.061 mm/ms. Eight events in a 600-ms IOI sequence are shown. <a href="//cloudflare.jove.com/files/ftp_upload/56205/56205fig1large.jpg" target="_blank">Please click here to view a larger version of this figure.</a>

<table border="0" cellpadding="0" cellspacing="0" width="747">
	<tbody>
		<tr height="21">
			<td height="21" style="height:21px;width:216px;">Psychtoolbox</td>
			<td style="width:189px;">http://psychtoolbox.org</td>
			<td style="width:175px;">3.0.12</td>
			<td style="width:167px;"></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">MATLAB</td>
			<td>MathWorks</td>
			<td>7.11.0 (R2010b)</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Adobe Photoshop</td>
			<td>Adobe&#160;Systems</td>
			<td>Adobe Photoshop CS6</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">computer monitor</td>
			<td>AOC</td>
			<td>G2460PQU/BR LCD</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">headphone</td>
			<td>PHILIPS</td>
			<td>SHM6500</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">computer keyboard</td>
			<td>Dell</td>
			<td>kb113t</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">smart phone</td>
			<td>Apple</td>
			<td>iphone6s</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">IBM SPSS Statistics</td>
			<td>IBM</td>
			<td>IBM SPSS Statistics 21</td>
			<td></td>
		</tr>
	</tbody>
</table>

bouncing ball with a uniformly varying velocity in a metronome synchronization task

Sensorimotor synchronization (SMS), a fundamental human ability to coordinate movements with external rhythms, has long been thought to be modality specific. In the canonical metronome synchronization task that requires tapping a finger along with an isochronous sequence, a well-established finding is that synchronization is much more stable to an auditory sequence consisting of auditory tones than to a visual sequence consisting of visual flashes. However, recent studies have shown that periodically moving visual stimuli can substantially improve synchronization compared with visual flashes. In particular, synchronization of a visual bouncing ball that has a uniformly varying velocity was found to be not less stable than synchronization of auditory tones. Here, the current protocol describes the application of the bouncing ball with a uniformly varying velocity in a metronome synchronization task. The usage of the bouncing ball in sequences with different inter-onset intervals (IOI) is included. The representative results illustrate synchronization performance of the bouncing ball, as compared with the performances of auditory tones and visual flashes. Given its comparable synchronization performance to that of auditory tones, the bouncing ball is of particular importance for addressing the current research topic of whether modality-specific mechanisms underlay SMS.

One of the best-known results in SMS studies is that metronome synchronization is much more stable to an auditory sequence consisting of auditory tones than to a visual sequence consisting of visual flashes1, suggesting modality-specific mechanisms of SMS2. However, recent studies have shown that periodically moving visual stimuli can substantially improve synchronization compared to visual flashes3,<sup cl...

Watch this Scientific Journal Video about Bouncing Ball with a Uniformly Varying Velocity in a Metronome Synchronization Task at JoVE.com

Bouncing Ball with a Uniformly Varying Velocity in a Metronome Synchronization Task

The purpose of this protocol is to introduce the application of a bouncing ball with a uniformly varying velocity in a metronome synchronization task.

Sensorimotor synchronization (SMS), a fundamental human ability to coordinate movements with external rhythms, has long been thought to be modality ...

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5.9K Views.  Sun Yat-Sen University. The purpose of this protocol is to introduce the application of a bouncing ball with a uniformly varying velocity in a metronome synchronization task. 

Video: Bouncing Ball with a Uniformly Varying Velocity in a Metronome Synchronization Task

The Crossmodal Congruency Task as a Means to Obtain an Objective Behavioral Measure in the Rubber Hand Illusion Paradigm

The rubber hand illusion (RHI) is a popular experimental paradigm. Participants view touch on an artificial rubber hand while the participants' own hidden hand is touched. If the viewed and felt touches are given at the same time then this is sufficient to induce the compelling experience that the rubber hand is one's own hand. The RHI can be used to investigate exactly how the brain constructs distinct body representations for one's own body. Such representations are crucial for successful interactions with the external world. To obtain a subjective measure of the RHI, researchers typically ask participants to rate statements such as "I felt as if the rubber hand were my hand". Here we demonstrate how the crossmodal congruency task can be used to obtain an objective behavioral measure within this paradigm.
The variant of the crossmodal congruency task we employ involves the presentation of tactile targets and visual distractors. Targets and distractors are spatially congruent (i.e. same finger) on some trials and incongruent (i.e. different finger) on others. The difference in performance between incongruent and congruent trials - the crossmodal congruency effect (CCE) - indexes multisensory interactions. Importantly, the CCE is modulated both by viewing a hand as well as the synchrony of viewed and felt touch which are both crucial factors for the RHI.
The use of the crossmodal congruency task within the RHI paradigm has several advantages. It is a simple behavioral measure which can be repeated many times and which can be obtained during the illusion while participants view the artificial hand. Furthermore, this measure is not susceptible to observer and experimenter biases. The combination of the RHI paradigm with the crossmodal congruency task allows in particular for the investigation of multisensory processes which are critical for modulations of body representations as in the RHI.

We demonstrate how an objective measure can be employed in the widely employed rubber hand illusion paradigm. This measure is obtained by modifying the well-established crossmodal congruency task. This task allows the investigation of multisensory processes which are critical for modulations of body representations as in the rubber hand illusion.

The rubber hand illusion (RHI) is a popular experimental paradigm. Participants view touch on an artificial rubber hand while the participants' own hidden ...

Measurement of Fronto-limbic Activity Using an Emotional Oddball Task in Children with Familial High Risk for Schizophrenia

Adolescence is a critical developmental period where the early symptoms of schizophrenia frequently emerge. First-degree relatives of people with schizophrenia who are at familial high risk (FHR) may show similar cognitive and emotional changes. However, the neurological changes underlying the emergence of these symptoms remain unclear. This study sought to identify differences in frontal, striatal, and limbic regions in children and adolescents with FHR using functional magnetic resonance imaging. Groups of 21 children and adolescents at FHR and 21 healthy controls completed an emotional oddball task that relied on selective attention and the suppression of task-irrelevant emotional information. The standard oddball task was modified to include aversive and neutral distractors in order to examine potential group differences in both emotional and executive processing. This task was designed specifically to allow for children and adolescents to complete by keeping the difficulty and emotional image content age-appropriate. Furthermore, we demonstrate a technique for suitable fMRI registration for children and adolescent participants. This paradigm may also be applied in future studies to measure changes in neural activity in other populations with hypothesized developmental changes in executive and emotional processing.

This paper describes how to use the emotional oddball task and fMRI to measure brain activation in children and adolescents at familial high risk for schizophrenia (FHR).&#160;FMRI was used to measure differences in fronto-striato-limbic regions during an emotional oddball task. Children with FHR exhibited abnormal functional activation during adolescence.

Adolescence is a critical developmental period where the early symptoms of schizophrenia frequently emerge. First-degree relatives of people with ...

The 5-Choice Serial Reaction Time Task: A Task of Attention and Impulse Control for Rodents

This protocol describes the 5-choice serial reaction time task, which is an operant based task used to study attention and impulse control in rodents. Test day challenges, modifications to the standard task, can be used to systematically tax the neural systems controlling either attention or impulse control. Importantly, these challenges have consistent effects on behavior across laboratories in intact animals and can reveal either enhancements or deficits in cognitive function that are not apparent when rats are only tested on the standard task. The variety of behavioral measures that are collected can be used to determine if other factors (i.e., sedation, motivation deficits, locomotor impairments) are contributing to changes in performance. The versatility of the 5CSRTT is further enhanced because it is amenable to combination with pharmacological, molecular, and genetic techniques.

This protocol describes the 5-choice serial reaction time task, which is an operant based task used to study attention and impulse control in rodents. Test day challenges, which are modifications of the standard task, increase flexibility of the task and can be combined with other manipulations to more fully characterize behavior.

This protocol describes the 5-choice serial reaction time task, which is an operant based task used to study attention and impulse control in rodents. ...

Using the Threat Probability Task to Assess Anxiety and Fear During Uncertain and Certain Threat

Fear of certain threat and anxiety about uncertain threat are distinct emotions with unique behavioral, cognitive-attentional, and neuroanatomical components. Both anxiety and fear can be studied in the laboratory by measuring the potentiation of the startle reflex. The startle reflex is a defensive reflex that is potentiated when an organism is threatened and the need for defense is high. The startle reflex is assessed via electromyography (EMG) in the orbicularis oculi muscle elicited by brief, intense, bursts of acoustic white noise (i.e., &#8220;startle probes&#8221;). Startle potentiation is calculated as the increase in startle response magnitude during presentation of sets of visual threat cues that signal delivery of mild electric shock relative to sets of matched cues that signal the absence of shock (no-threat cues). In the Threat Probability Task, fear is measured via startle potentiation to high probability (100% cue-contingent shock; certain) threat cues whereas anxiety is measured via startle potentiation to low probability (20% cue-contingent shock; uncertain) threat cues. Measurement of startle potentiation during the Threat Probability Task provides an objective and easily implemented alternative to assessment of negative affect via self-report or other methods (e.g., neuroimaging) that may be inappropriate or impractical for some researchers. Startle potentiation has been studied rigorously in both animals (e.g., rodents, non-human primates) and humans which facilitates animal-to-human translational research. Startle potentiation during certain and uncertain threat provides an objective measure of negative affective and distinct emotional states (fear, anxiety) to use in research on psychopathology, substance use/abuse and broadly in affective science. As such, it has been used extensively by clinical scientists interested in psychopathology etiology and by affective scientists interested in individual differences in emotion.

Potentiation of the startle reflex is measured via electromyography of the orbicularis oculi muscle during low (uncertain) and high (certain) probability electric shock threat in the Threat Probability Task. This provides an objective measure of distinct negative emotional states (fear/anxiety) for research on psychopathology, substance use/abuse, and broad affective science.

Fear of certain threat and anxiety about uncertain threat are distinct emotions with unique behavioral, cognitive-attentional, and neuroanatomical ...

The Attentional Set Shifting Task: A Measure of Cognitive Flexibility in Mice

Cognitive impairment, particularly involving dysfunction of circuitry within the prefrontal cortex (PFC), represents a core feature of many neuropsychiatric and neurodevelopmental disorders, including depression, post-traumatic stress disorder, schizophrenia and autism spectrum disorder. Deficits in cognitive function also represent the most difficult symptom domain&#160;to successfully treat, as serotonin reuptake inhibitors and tricyclic antidepressants have only modest effects. Functional neuroimaging studies and postmortem analysis of human brain tissue implicate the PFC as being a primary region of dysregulation in patients with these disorders. However, preclinical behavioral assays used to assess these deficits in mouse models which can be readily manipulated genetically and could provide the basis for studies of new treatment avenues have been underutilized. Here we describe the adaptation of a behavioral assay, the attentional set shifting task (AST), to be performed in mice to assess prefrontal cortex mediated cognitive deficits. The neural circuits underlying behavior during the AST are highly conserved across humans, nonhuman primates and rodents, providing excellent face, construct and predictive validity.

The goal of this protocol is to perform a behavioral assay such as the attentional set shifting task (AST) to assess prefrontal cortex-mediated cognitive flexibility in mice.

Cognitive impairment, particularly involving dysfunction of circuitry within the prefrontal cortex (PFC), represents a core feature of many ...

fMRI Validation of fNIRS Measurements During a Naturalistic Task

We present a method to compare brain activity recorded with near-infrared spectroscopy (fNIRS) in a dance video game task to that recorded in a reduced version of the task using fMRI (functional magnetic resonance imaging). Recently, it has been shown that fNIRS can accurately record functional brain activities equivalent to those concurrently recorded with functional magnetic resonance imaging for classic psychophysical tasks and simple finger tapping paradigms. However, an often quoted benefit of fNIRS is that the technique allows for studying neural mechanisms of complex, naturalistic behaviors that are not possible using the constrained environment of fMRI. Our goal was to extend the findings of previous studies that have shown high correlation between concurrently recorded fNIRS and fMRI signals to compare neural recordings obtained in fMRI procedures to those separately obtained in naturalistic fNIRS experiments. Specifically, we developed a modified version of the dance video game Dance Dance Revolution (DDR) to be compatible with both fMRI and fNIRS imaging procedures. In this methodology we explain the modifications to the software and hardware for compatibility with each technique as well as the scanning and calibration procedures used to obtain representative results. The results of the study show a task-related increase in oxyhemoglobin in both modalities and demonstrate that it is possible to replicate the findings of fMRI using fNIRS in a naturalistic task. This technique represents a methodology to compare fMRI imaging paradigms which utilize a reduced-world environment to fNIRS in closer approximation to naturalistic, full-body activities and behaviors. Further development of this technique may apply to neurodegenerative diseases, such as Parkinson&#8217;s disease, late states of dementia, or those with magnetic susceptibility which are contraindicated for fMRI scanning.

We present a method to compare functional brain activity recorded during a naturalistic task using fNIRS with activity recorded during fMRI.

We present a method to compare brain activity recorded with near-infrared spectroscopy (fNIRS) in a dance video game task to that recorded in a reduced ...

A Dual Task Procedure Combined with Rapid Serial Visual Presentation to Test Attentional Blink for Nontargets

When viewers search for targets in a rapid serial visual presentation (RSVP) stream, if two targets are presented within about 500 msec of each other, the first target may be easy to spot but the second is likely to be missed. This phenomenon of attentional blink (AB) has been widely studied to probe the temporal capacity of attention for detecting visual targets. However, with the typical procedure of AB experiments, it is not possible to examine how the processing of non-target items in RSVP may be affected by attention. This paper describes a novel dual task procedure combined with RSVP to test effects of AB for nontargets at varied stimulus onset asynchronies (SOAs). In an exemplar experiment, a target category was first displayed, followed by a sequence of 8 nouns. If one of the nouns belonged to the target category, participants would respond &#8216;yes&#8217; at the end of the sequence, otherwise participants would respond &#8216;no&#8217;. Two 2-alternative forced choice memory tasks followed the response to determine if participants remembered the words immediately before or after the target, as well as a random word from another part of the sequence. In a second exemplar experiment, the same design was used, except that 1) the memory task was counterbalanced into two groups with SOAs of either 120 or 240 msec and 2) three memory tasks followed the sequence and tested remembrance for nontarget nouns in the sequence that could be anywhere from 3 items prior the target noun position to 3 items following the target noun position. Representative results from a previously published study demonstrate that our procedure can be used to examine divergent effects of attention that not only enhance targets but also suppress nontargets. Here we show results from a representative participant that replicated the previous finding.&#160;

This paper describes a novel dual task procedure combined with Rapid Serial Visual Presentation to look at attentional blink at varied stimulus onset asynchronies. This experimental procedure differed from others in that it tested attentional blink for nontargets.

When viewers search for targets in a rapid serial visual presentation (RSVP) stream, if two targets are presented within about 500 msec of each other, the ...

Quantifying Learning in Young Infants: Tracking Leg Actions During a Discovery-learning Task

Task-specific actions emerge from spontaneous movement during infancy. It has been proposed that task-specific actions emerge through a discovery-learning process. Here a method is described in which 3-4 month old infants learn a task by discovery and their leg movements are captured to quantify the learning process. This discovery-learning task uses an infant activated mobile that rotates and plays music based on specified leg action of infants. Supine infants activate the mobile by moving their feet vertically across a virtual threshold. This paradigm is unique in that as infants independently discover that their leg actions activate the mobile, the infants&#8217; leg movements are tracked using a motion capture system allowing for the quantification of the learning process. Specifically, learning is quantified in terms of the duration of mobile activation, the position variance of the end effectors (feet) that activate the mobile, changes in hip-knee coordination patterns, and changes in hip and knee muscle torque. This information describes infant exploration and exploitation at the interplay of person and environmental constraints that support task-specific action. Subsequent research using this method can investigate how specific impairments of different populations of infants at risk for movement disorders influence the discovery-learning process for task-specific action.

A method is described in which 3-4 month old infants learn a task by discovery and their leg movements are captured to quantify the learning process.

Task-specific actions emerge from spontaneous movement during infancy. It has been proposed that task-specific actions emerge through a discovery-learning ...

Acquisition of a High-precision Skilled Forelimb Reaching Task in Rats

Movements are the main measurable output of central nervous system function. Developing behavioral paradigms that allow detailed analysis of motor learning and execution is of critical importance in order to understand the principles and processes that underlie motor function. Here we present a paradigm to study movement acquisition within a daily session of training (within-session) representing the fast learning component and primary acquisition as well as skilled motor learning over several training sessions (between-session) representing the slow learning component and consolidation of the learned task. This behavioral paradigm increases the degree of difficulty and complexity of the motor skill task due to two features: First, the animal realigns its body prior to each pellet retrieval forcing renewed orientation and preventing movement execution from the same angle. Second, pellets are grasped from a vertical post that matches the diameter of the pellet and is placed in front of the cage. This requires a precise grasp for successful pellet retrieval and thus prevents simple pulling of the pellet towards the animal. In combination with novel genetics, imaging and electrophysiological technologies, this behavioral method will aid to understand the morphological, anatomical and molecular underpinnings of motor learning and memory.

A paradigm is presented to analyze the acquisition of a high-precision skilled forelimb reaching task in rats.

Movements are the main measurable output of central nervous system function. Developing behavioral paradigms that allow detailed analysis of motor ...

The Knob Supination Task: A Semi-automated Method for Assessing Forelimb Function in Rats

Tasks that accurately measure dexterity in animal models are critical to understand hand function. Current rat behavioral tasks that measure dexterity largely use video analysis of reaching or food manipulation. While these tasks are easy to implement and are robust across disease models, they are subjective and laborious for the experimenter. Automating traditional tasks or creating new automated tasks can make the tasks more efficient, objective, and quantitative. Since rats are less dexterous than primates, central nervous system (CNS) injury produces more subtle deficits in dexterity, however, supination is highly affected in rodents and crucial to hand function in primates. Therefore, we designed a semi-automated task that measures forelimb supination in rats. Rats are trained to reach and grasp a knob-shaped manipulandum and turn the manipulandum in supination to receive a reward. Rats can acquire the skill within 20 &plusmn; 5 days. While the early part of training is highly supervised, much of the training is done without direct supervision. The task reliably and reproducibly captures subtle deficits after injury and shows functional recovery that accurately reflects clinical recovery curves. Analysis of data is performed by specialized software through a graphical user interface that is designed to be intuitive. We also give solutions to common problems encountered during training, and show that minor corrections to behavior early in training produce reliable acquisition of supination. Thus, the knob supination task provides efficient and quantitative evaluation of a critical movement for dexterity in rats.

This manuscript describes a semi-automated task that quantifies supination in rats. Rats reach, grasp, and supinate a spherical manipulandum. The rat is rewarded with a pellet if the turn angle exceeds a criterion set by the user. This task increases throughput, sensitivity to injury, and objectivity compared to traditional tasks.

Tasks that accurately measure dexterity in animal models are critical to understand hand function. Current rat behavioral tasks that measure dexterity ...