The authors would like to thank Ralf K&#252;hne for technical support. This work was funded by the Deutsche Forschungsgemeinschaft (DFG) and the Bundesministerium f&#252;r Bildung und Forschung (BMBF #01GM1103A). This is an EU Joint Programme-Neurodegenerative Disease Research (JPND) project. The project is supported through the following organizations under the aegis of JPND-e.g., Germany, Bundesministerium f&#252;r Bildung und Forschung (BMBF, FKZ), Sweden, Vetenskapr&#229;det Sverige, Poland, Narodowe Centrum Bada&#324; i Rozwoju (NCBR).

The study was approved by the Ethics Committee of the University of Ulm (Statement No. 19/12) and the protocol described therefore follows their guidelines. All participants gave written informed consent.
1. Stimuli and Testing Environment
<ol>
	<li>To keep distractions to a minimum perform the research in a dark or a very dimly lit and quiet room.</li>
	<li>Use an appropriate eye tracking device. 
	NOTE: There are a wide variety of devices available to perform eye movement studies. In the present research a portable eye movement recording device with goggles was used, which synchronously measure binocular eye positions, using two integrated cameras with an infrared light emitting diode (IR LEDs), one for each eye18.
	<ol>
		<li>To ensure optimal eye-tracking, adjust the cameras manually by tilting them in all 6 degrees of freedom (3 translational, 3 rotational) until eye movement detection is optimal. 
		NOTE: The measurements of the system are displayed in real-time on an experimenter&#39;s screen to monitor recording quality and participants&#39; response behavior. The key features of the system are described below and detailed specifications are given in Table 1.</li>
	</ol>
	</li>
	<li>Implement a standardized oculomotor testing paradigm, which is able to detect deficits in eye movement control. 
	NOTE: This can be a series of tasks like smooth pursuit or saccade tasks, in which participants with impaired eye movement control perform badly (e.g., the methods described by Gorges et al. 201511). These participants have to be excluded from further testing.</li>
	<li>Present tasks using appropriate software that projects the stimuli on a hemi-cylindrical screen via a projector mounted above the subject&#39;s head11. Additionally, ensure that a red laser spot (diameter: 0.3&#176;, position: 10&#176; vertical) is present for the D2-test.</li>
	<li>Seat the participants on an elevated chair with an adjustable chin rest, so that eye-to-screen distance is approximately 150 cm.</li>
	<li>Use set A and B of the CPM (12 stimuli for each set) for the first part of the experiment. Show these stimuli as 22&#176; long/15&#176; high matrices with six possible alternatives depicted below, which might fit in a 6&#176; wide and 5&#176; high blank space cut out from the matrix.</li>
	<li>For the D2-test, use the five blocks with 47 stimuli, corresponding to line 2 - 6 of the standard D2-test15, and depict them one stimulus after another in the middle of the screen with a height of 11&#176; and a width of 2.5&#176;. Make sure each stimulus lasts for 2,000 msec.</li>
</ol>
2. Running the Experiment
<ol>
	<li>Before the experiment starts, ask participants to fill out a written informed consent form to ensure the study is in accordance with ethical standards.</li>
	<li>Give general instructions concerning the purpose and procedure of the experiment and control for CNS-active drugs, i.e., ask the participant if he/she is currently taking any medication which affects alertness and therefore cognitive performance.</li>
	<li>Turn off all devices which might be a potential disturbance, such as mobile phones or pagers.</li>
	<li>Seat participants comfortably with the chin rest in optimal position. Ensure that the whole screen is visible and ask the participant to maintain posture during the whole experiment.</li>
	<li>Ask participants to place their head on the chin rest and place the videooculography goggles onto their head. Adjust them to individual head size/shape. 
	NOTE: Thereby, the best possible compromise between comfort for the participant and minimal risk of unwanted slipping during measurement must be made.</li>
	<li>Make sure that both eyes are visible on the experimenter&#39;s screen, where the images of the two eye movement recording cameras within the goggles are displayed and then focus the cameras to center the images on the screen. 
	NOTE: This is important for optimal detection and tracking of the pupil as an improper acuity can lead to a disturbed signal.</li>
	<li>To ensure continuous recording of eye movements at all times, start calibration of the system by instructing the participant to look in each corner of the hemi-cylindrical screen. In case the signal is lost, change the angle of the camera tracking the respective pupil of the eye to resolve the problem.</li>
	<li>Start the standardized oculomotor testing paradigm described above and exclude all patients with substantial visual impairments as these will cause corrupted task performance.</li>
	<li>Instruct the participant to track a single spot on the screen, oscillating horizontally (&#177; 20&#176;) and then vertically (&#177; 15&#176;) with a frequency of 0.125 Hz to map the non-calibrated orthogonalized &#39;raw&#39; data from the eye movement recording device with respect to the &#39;true&#39; orthogonalized eye position for calibration of the system.</li>
	<li>Check if calibration is acceptable, i.e., if the &#39;true&#39; eye movement and the &#39;raw&#39; data are spatially and temporally synchronized and then instruct the participant to not move the head as this might result in bad data quality. 
	NOTE: Position of the videooculography device and the subject is expected to be stationary during the course of the experiment, so that there is no need for re-calibration.</li>
	<li>Explain the procedure of the training session for the CPM:
	<ol>
		<li>Instruct the subjects to identify the missing pieces below the upcoming matrices displayed on the hemi-cylindrical screen for which they have infinite time. After making a choice, have the subject close their eyes for at least 250 msec to start off a green frame outlining all of the possible alternatives of missing pieces for 1,500 msec each.</li>
		<li>Have the participant choose the alternative they think is correct by closing their eyes for at least 250 msec while their choice is enframed.</li>
		<li>Project the choice separately on the hemi-cylindrical screen. Ask the participants to confirm. If the participant confirms, instruct them to close their eyes again for at least 250 msec.</li>
		<li>Instruct the participants that the next stimulus (matrix with 6 alternatives of missing pieces) will automatically (again, presented by the software described in step 2) appear and that this will be done four times with training stimuli taken from set AB of the CPM14.</li>
	</ol>
	</li>
	<li>Answer any questions subjects might have about the procedure. Then, instruct the participants to choose the missing piece of the matrix, as they have learned during the training session and start the CPM (Figure 1).</li>
	<li>Explain the procedure of the training session for the D2-test:
	<ol>
		<li>Instruct participants to direct their gaze to the center of the screen and observe 47 stimuli separately (47 d&#39;s corresponding to line 1 of the standard D2-test).</li>
		<li>Instruct the participants to look at the red laser spot positioned above the stimuli whenever a &#34;d&#34; with two dashes is presented until the next stimulus appears. NOTE: If no target stimulus is presented the gaze needs to be focused at the center of the screen where the next stimulus will be presented.</li>
	</ol>
	</li>
	<li>Answer any questions subjects might have about the procedure. Then, instruct the participant to proceed for the following five blocks of 47 stimuli, similar to the training session and start the D2-test.</li>
	<li>For quality control, inspect the data obtained from each session for each subject carefully (visually by a trained experimenter). Check if data quality is corrupted, for example due to technical difficulties, corrupted eye movements or misunderstandings.</li>
	<li>Thank subjects for their participation and answer all questions during the experiment.</li>
</ol>

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L., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=An+eye-tracking+version+of+the+trail-making+test.">An eye-tracking version of the trail-making test.</a> PLoS One. 8 (12), 84061 (2013).</li><li>Keller, J., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Eye-tracking+controlled+cognitive+function+tests+in+patients+with+amyotrophic+lateral+sclerosis:+a+controlled+proof-of-principle+study.">Eye-tracking controlled cognitive function tests in patients with amyotrophic lateral sclerosis: a controlled proof-of-principle study.</a> J. Neurol. 262 (8), 1918-1926 (2015).</li><li>Raven, J. C., Court, J. H., Raven, J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> Manual for Raven's progressive matrices and vocabulary scales. Section 2, the coloured progressive matrices. , (1998).</li><li>Brickenkamp, R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> Aufmerksamkeits-Belastungs-Test (Test d2), 8th edn. , (1994).</li><li>Elamin, M., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Cognitive+changes+predict+functional+decline+in+ALS.">Cognitive changes predict functional decline in ALS.</a> Neurology. 80 (17), 1590-1597 (2013).</li><li>Ludolph, A. 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Psychiatry Law. 43 (2), 210-217 (2015).</li><li>K&#252;bler, A., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Patients+with+ALS+can+use+sensorimotor+rhythms+to+operate+a+brain-computer+interface.">Patients with ALS can use sensorimotor rhythms to operate a brain-computer interface.</a> Neurology. 64 (10), 1775-1777 (2005).</li><li>Connolly, S., Galvin, M., Hardiman, O. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=End-of-life+management+in+patients+with+amyotrophic+lateral+sclerosis.">End-of-life management in patients with amyotrophic lateral sclerosis.</a> Lancet Neurol. 14 (4), 435-442 (2015).</li></ol>

The authors declare that they have no competing financial interests.

It is a challenging task to successfully assess the cognitive status of patients with ALS who are unable to speak and write. The use of videooculography systems provides a promising approach. The hereby presented technique is reliable in detecting cognitive deficits, which play a pivotal role in the context of carer burden and disease management20 in ALS patients. Also, the oculomotor versions of the CPM and the D2-test correlate significantly with their respective standard paper-pencil versions, but further s...

Amyotrophic lateral sclerosis (ALS) is a fatal neurodegenerative disorder usually leading to death within 3 to 5 years. In the course of the pathology, patients present with progressive loss of respiratory and bulbar functioning as well as impairments in movement abilities1. It shares some clinical, pathological, and genetic features with frontotemporal dementia2 and it is well documented that about 30% of ALS patients exhibit cognitive deficits3. These deficits are most prominent in the domains of executive function, verbal fluency and language4 and have an influence on survival5, compliance6 and carer burden7. Thus, reliable neuropsychological assessment is crucial in this disease.
Advancing impairments in motor and speech abilities are, however, a limiting factor for thorough evaluation of cognitive abilities in later stages of the disease8. Here, oculomotor based approaches seem to be very promising, as basic eye movement control remains intact for a comparably long time during the course of ALS for the majority of patients9. Eye-tracking parameters itself have been used to gain information about the cognitive status of patients with ALS10 and also correlate with the sequential spreading pattern of ALS11. Eye movement as a means to control cognitive tests in the context of ALS has also been studied in previous works. One study has successfully demonstrated its usability in healthy controls using an oculomotor based version of the Trail-Making Test12, whereas another found it suitable to distinguish between healthy controls and ALS patients based on cognitive performance and to discriminate between cognitively more and less impaired patients13.
The research described here used an oculomotor based methodology to study cognitive impairments in ALS patients, specifically in the domain of executive functioning. Two well validated and commonly used neuropsychological tests were adapted to eye movement control: the Raven&#39;s coloured progressive matrices (CPM)14 and the D2-test15. The CPM is a non-verbal instrument used to measure executive and visuospatial abilities as well as fluid intelligence. The D2-test is also a non-verbal tool used to uncover executive dysfunction in the domains of selective and sustained attention and visual processing speed. Both are widely used clinical tools which have been successfully employed in previous studies assessing potential cognitive decline during the course of the disease16 and the neuropsychological status of ALS patients compared to healthy controls17.
The goal of this work was to show the requirements for successful evaluation of cognitive deficits in ALS independent of movement and speech disabilities using a reliable, eye-tracking based version of the CPM and the D2-test. Importantly, the method described here has the potential to be expanded to study other populations of patients with severe motor impairments.

<table border="0" cellpadding="0" cellspacing="0" width="1081">
	<tbody>
		<tr height="21">
			<td>EyeSeeCam</td>
			<td>EyeSeeTec GmbH; 82256 F&#252;rstenfeldbruck, Germany</td>
			<td></td>
			<td>Videooculography device</td>
		</tr>
	</tbody>
</table>

eye-tracking control to assess cognitive functions in patients with amyotrophic lateral sclerosis

Amyotrophic lateral sclerosis (ALS) is a neurodegenerative disorder with pathological involvement of upper and lower motoneurons, subsequently leading to progressive loss of motor and speech abilities. In addition, cognitive functions are impaired in a subset of patients. To evaluate these potential deficits in severely physically impaired ALS patients, eye-tracking is a promising means to conduct cognitive tests. The present article focuses on how eye movements, an indirect means of communication for physically disabled patients, can be utilized to allow for detailed neuropsychological assessment. The requirements, in terms of oculomotor parameters that have to be met for sufficient eye-tracking in ALS patients are presented. The properties of stimuli, including type of neuropsychological tests and style of presentation, best suited to successfully assess cognitive functioning, are also described. Furthermore, recommendations regarding procedural requirements are provided. Overall, this methodology provides a reliable, easy to administer and fast approach for assessing cognitive deficits in patients who are unable to speak or write such as patients with severe ALS. The only confounding factor might be deficits in voluntary eye movement control in a subset of ALS patients.

For the purpose of the research presented here, i.e.,&#160;the development of a reliable oculomotor based neuropsychological assessment for ALS patients, in-house developed software stores the subject&#39;s choices of the CPM in a separate file, allowing for manual computation of the percentage of correct answers. For the D2-test, a record of the vertical eye movements is manually analyzed using a threshold of + 5&#176; for detection of a relevant response. Recordings are assigne...

Watch this Scientific Journal Video about Eye-Tracking Control to Assess Cognitive Functions in Patients with Amyotrophic Lateral Sclerosis at JoVE.com

Eye-Tracking Control to Assess Cognitive Functions in Patients with Amyotrophic Lateral Sclerosis

Cognitive deficits are common in about one third of patients with amyotrophic lateral sclerosis, a neurological condition leading to progressive impairments in speech and movement abilities. To conduct cognitive tests in patients unable to speak or write a reliable and easy to administer eye-tracking paradigm was developed.

Amyotrophic lateral sclerosis (ALS) is a neurodegenerative disorder with pathological involvement of upper and lower motoneurons, subsequently leading to ...

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8.1K Views.  Ulm University. Cognitive deficits are common in about one third of patients with amyotrophic lateral sclerosis, a neurological condition leading to progressive impairments in speech and movement abilities. To conduct cognitive tests in patients unable to speak or write a reliable and easy to administer eye-tracking paradigm was developed.

Video: Eye-Tracking Control to Assess Cognitive Functions in Patients with Amyotrophic Lateral Sclerosis

A Method for Investigating Age-related Differences in the Functional Connectivity of Cognitive Control Networks Associated with Dimensional Change Card Sort Performance

The ability to adjust behavior to sudden changes in the environment develops gradually in childhood and adolescence. For example, in the Dimensional Change Card Sort task, participants switch from sorting cards one way, such as shape, to sorting them a different way, such as color. Adjusting behavior in this way exacts a small performance cost, or switch cost, such that responses are typically slower and more error-prone on switch trials in which the sorting rule changes as compared to repeat trials in which the sorting rule remains the same. The ability to flexibly adjust behavior is often said to develop gradually, in part because behavioral costs such as switch costs typically decrease with increasing age. Why aspects of higher-order cognition, such as behavioral flexibility, develop so gradually remains an open question. One hypothesis is that these changes occur in association with functional changes in broad-scale cognitive control networks. On this view, complex mental operations, such as switching, involve rapid interactions between several distributed brain regions, including those that update and maintain task rules, re-orient attention, and select behaviors. With development, functional connections between these regions strengthen, leading to faster and more efficient switching operations. The current video describes a method of testing this hypothesis through the collection and multivariate analysis of fMRI data from participants of different ages.

This video presents a method of examining age-related changes in functional connectivity of cognitive control networks engaged by targeted tasks/processes. The technique is based on multi-variate analysis of fMRI data.

The ability to adjust behavior to sudden changes in the environment develops gradually in childhood and adolescence. For example, in the Dimensional ...

A Fully Automated Rodent Conditioning Protocol for Sensorimotor Integration and Cognitive Control Experiments

Rodents have been traditionally used as a standard animal model in laboratory experiments involving a myriad of sensory, cognitive, and motor tasks. Higher cognitive functions that require precise control over sensorimotor responses such as decision-making and attentional modulation, however, are typically assessed in nonhuman primates. Despite the richness of primate behavior that allows multiple variants of these functions to be studied, the rodent model remains an attractive, cost-effective alternative to primate models. Furthermore, the ability to fully automate operant conditioning in rodents adds unique advantages over the labor intensive training of nonhuman primates while studying a broad range of these complex functions.
Here, we introduce a protocol for operantly conditioning rats on performing working memory tasks. During critical epochs of the task, the protocol ensures that the animal's overt movement is minimized by requiring the animal to 'fixate' until a Go cue is delivered, akin to nonhuman primate experimental design. A simple two alternative forced choice task is implemented to demonstrate the performance. We discuss the application of this paradigm to other tasks.

A fully automated protocol for rodent operant conditioning is proposed. The protocol relies on precise temporal control of behavioral events to investigate the extent to which this control influences neural activity underlying sensorimotor integration and cognitive control experiments.

Rodents have been traditionally used as a standard animal model in laboratory experiments involving a myriad of sensory, cognitive, and motor tasks. ...

Uncovering Beat Deafness: Detecting Rhythm Disorders with Synchronized Finger Tapping and Perceptual Timing Tasks

A set of behavioral tasks for assessing perceptual and sensorimotor timing abilities in the general population (i.e., non-musicians) is presented here with the goal of uncovering rhythm disorders, such as beat deafness. Beat deafness is characterized by poor performance in perceiving durations in auditory rhythmic patterns or poor synchronization of movement with auditory rhythms (e.g., with musical beats). These tasks include the synchronization of finger tapping to the beat of simple and complex auditory stimuli and the detection of rhythmic irregularities (anisochrony detection task) embedded in the same stimuli. These tests, which are easy to administer, include an assessment of both perceptual and sensorimotor timing abilities under different conditions (e.g., beat rates and types of auditory material) and are based on the same auditory stimuli, ranging from a simple metronome to a complex musical excerpt. The analysis of synchronized tapping data is performed with circular statistics, which provide reliable measures of synchronization accuracy (e.g., the difference between the timing of the taps and the timing of the pacing stimuli) and consistency. Circular statistics on tapping data are particularly well-suited for detecting individual differences in the general population. Synchronized tapping and anisochrony detection are sensitive measures for identifying profiles of rhythm disorders and have been used with success to uncover cases of poor synchronization with spared perceptual timing. This systematic assessment of perceptual and sensorimotor timing can be extended to populations of patients with brain damage, neurodegenerative diseases (e.g., Parkinson&#8217;s disease), and developmental disorders (e.g., Attention Deficit Hyperactivity Disorder).

Behavioral tasks that allow for the assessment of perceptual and sensorimotor timing abilities in the general population (i.e., non-musicians) are presented. Synchronization of finger tapping to the beat of an auditory stimuli and detecting rhythmic irregularities provides a means of uncovering rhythm disorders.

A set of behavioral tasks for assessing perceptual and sensorimotor timing abilities in the general population (i.e., non-musicians) is presented here ...

Recording Mouse Ultrasonic Vocalizations to Evaluate Social Communication

Mice emit ultrasonic vocalizations in different contexts throughout development and in adulthood. These vocal signals are now currently used as proxies for modeling the genetic bases of vocal communication deficits. Characterizing the vocal behavior of mouse models carrying mutations in genes associated with neuropsychiatric disorders such as autism spectrum disorders will help to understand the mechanisms leading to social communication deficits. We provide here protocols to reliably elicit ultrasonic vocalizations in pups and in adult mice. This standardization will help reduce inter-study variability due to the experimental settings. Pup isolation calls are recorded throughout development from individual pups isolated from dam and littermates. In adulthood, vocalizations are recorded during same-sex interactions (without a sexual component) by exposing socially motivated males or females to an unknown same-sex conspecific. We also provide a protocol to record vocalizations from adult males exposed to an estrus female. In this context, there is a sexual component in the interaction. These protocols are established to elicit a large amount of ultrasonic vocalizations in laboratory mice. However, we point out the important inter-individual variability in the vocal behavior of mice, which should be taken into account by recording a minimal number of individuals (at least 12 in each condition). These recordings of ultrasonic vocalizations are used to evaluate the call rate, the vocal repertoire and the acoustic structure of the calls. Data are combined with the analysis of synchronous video recordings to provide a more complete view on social communication in mice. These protocols are used to characterize the vocal communication deficits in mice lacking ProSAP1/Shank2, a gene associated with autism spectrum disorders. More ultrasonic vocalizations recordings can also be found on the mouseTube database, developed to favor the exchange of such data.

Mouse ultrasonic vocalizations are used as proxies to model the genetic bases of vocal communication deficits in mouse models for neuropsychiatric disorders. The present protocol describes three experimental contexts that reliably elicit ultrasonic vocalizations from pups (throughout development) and adult mice (same-sex interactions, male-estrus female interactions).

Mice emit ultrasonic vocalizations in different contexts throughout development and in adulthood. These vocal signals are now currently used as proxies ...

A Method to Quantify Visual Information Processing in Children Using Eye Tracking

Visual problems that occur early in life can have major impact on a child's development. Without verbal communication and only based on observational methods, it is difficult to make a quantitative assessment of a child's visual problems. This limits accurate diagnostics in children under the age of 4 years and in children with intellectual disabilities. Here we describe a quantitative method that overcomes these problems. The method uses a remote eye tracker and a four choice preferential looking paradigm to measure eye movement responses to different visual stimuli. The child sits without head support in front of a monitor with integrated infrared cameras. In one of four monitor quadrants a visual stimulus is presented. Each stimulus has a specific visual modality with respect to the background, e.g., form, motion, contrast or color. From the reflexive eye movement responses to these specific visual modalities, output parameters such as reaction times, fixation accuracy and fixation duration are calculated to quantify a child's viewing behavior. With this approach, the quality of visual information processing can be assessed without the use of communication. By comparing results with reference values obtained in typically developing children from 0-12 years, the method provides a characterization of visual information processing in visually impaired children. The quantitative information provided by this method can be advantageous for the field of clinical visual assessment and rehabilitation in multiple ways. The parameter values provide a good basis to: (i) characterize early visual capacities and consequently to enable early interventions; (ii) compare risk groups and follow visual development over time; and (iii), construct an individual visual profile for each child.

A method is described to quantify the quality of visual information processing based on reflexive eye movements in response to specific visual modalities. Reaction times and fixation output parameters are used to characterize visual performance in children with and without visual impairments from 6 months of age.

Visual problems that occur early in life can have major impact on a child's development. Without verbal communication and only based on observational ...

Eye Tracking During Visually Situated Language Comprehension: Flexibility and Limitations in Uncovering Visual Context Effects

The present work is a description and an assessment of a methodology designed to quantify different aspects of the interaction between language processing and the perception of the visual world. The recording of eye-gaze patterns has provided good evidence for the contribution of both the visual context and linguistic/world knowledge to language comprehension. Initial research assessed object-context effects to test&#160;theories of modularity in language processing. In the introduction, we describe how subsequent investigations have taken the role of the wider visual context in language processing as a research topic in its own right, asking questions such as how our visual perception of events and of speakers contributes to&#160;comprehension informed by&#160;comprehenders&#39; experience. Among the examined aspects of the visual context are actions, events, a speaker&#39;s gaze, and emotional facial expressions, as well as spatial object configurations. Following an overview of the eye-tracking method and its different applications, we list the key steps of the methodology in the protocol, illustrating how to successfully use it to study visually-situated language comprehension. A final section presents three sets of representative results and illustrates the benefits and limitations of eye tracking for investigating the interplay between the perception of the visual world and language comprehension.

The present article reviews an eye-tracking methodology for studies on language comprehension. To obtain reliable data, key steps of the protocol must be followed. Among these are the correct set-up of the eye tracker (e.g., ensuring good quality of the eye and head images) and accurate calibration.

The present work is a description and an assessment of a methodology designed to quantify different aspects of the interaction between language processing ...

Comparing Eye-tracking Data of Children with High-functioning ASD, Comorbid ADHD, and of a Control Watching Social Videos

Children with autism spectrum disorders (ASD) are known to have sensory-perceptual processing deficits that weaken their abilities to attend and perceive social stimuli in daily living contexts. Since daily social episodes consist of subtle dynamic changes in social information, any failure to attend to or process subtle human nonverbal cues, such as facial expression, postures, and gestures, might lead to inappropriate social interaction. Traditional behavioral rating scales or assessment tools based on static social scenes have limitations in capturing the moment-to-moment changes in social scenarios. An eye-tracking assessment, which can be administered in a video-based mode, is therefore preferred, to augment clinical observation. In this study, using the single-case comparison design, the eye-tracking data of three participants, a child with autism spectrum disorder (ASD), another with comorbid attention deficit-hyperactive disorder (ADHD), and a neurotypical control, are captured while they view a video of social scenarios. The eye-tracking experiment has helped answer the research question: How does social attention differ between the three participants? By predefining areas of interest (AOIs), their visual attention on relevant or irrelevant social stimuli, how fast each participant attends to the first social stimuli appearing in the videos, for how long each participant continues to attend to those stimuli within the AOIs, and the gaze shifts between multiple social stimuli appearing concurrently in the same social scene are captured, compared, and analyzed in a video-based eye-tracking experiment.

This is a qualitative comparative case study analysis of eye-tracking data on the first moments of social video scenes as viewed by three participants: one with autism spectrum disorder, one with comorbid attention deficit-hyperactive disorder, and one neurotypical control.

Children with autism spectrum disorders (ASD) are known to have sensory-perceptual processing deficits that weaken their abilities to attend and perceive ...

Simultaneous Eye Tracking and Single-Neuron Recordings in Human Epilepsy Patients

Intracranial recordings from patients with intractable epilepsy provide a unique opportunity to study the activity of individual human neurons during active behavior. An important tool for quantifying behavior is eye tracking, which is an indispensable tool for studying visual attention. However, eye tracking is challenging to use concurrently with invasive electrophysiology and this approach has consequently been little used. Here, we present a proven experimental protocol to conduct single-neuron recordings with simultaneous eye tracking in humans. We describe how the systems are connected and the optimal settings to record neurons and eye movements. To illustrate the utility of this method, we summarize results that were made possible by this setup. This data shows how using eye tracking in a memory-guided visual search task allowed us to describe a new class of neurons called target neurons, whose response was reflective of top-down attention to the current search target. Lastly, we discuss the significance and solutions to potential problems of this setup. Together, our protocol and results suggest that single-neuron recordings with simultaneous eye tracking in humans are an effective method to study human brain function. It provides a key missing link between animal neurophysiology and human cognitive neuroscience.

We describe a method to conduct single-neuron recordings with simultaneous eye tracking in humans. We demonstrate the utility of this method and illustrate how we used this approach to obtain neurons in the human medial temporal lobe that encode targets of a visual search.

Intracranial recordings from patients with intractable epilepsy provide a unique opportunity to study the activity of individual human neurons during ...

Investigating the Deployment of Visual Attention Before Accurate and Averaging Saccades via Eye Tracking and Assessment of Visual Sensitivity

This experimental protocol was designed to investigate whether visual attention is obligatorily deployed at the endpoint of saccades. To this end, we recorded the eye position of human participants engaged in a saccade task via eye tracking and assessed visual orientation discrimination performance at various locations during saccade preparation. Importantly, instead of using a single saccade target paradigm for which the saccade endpoint typically coincides roughly with the target, this protocol comprised the presentation of two nearby saccade targets, leading to a distinct spatial dissociation between target locations and saccade endpoint on a substantial number of trials. The paradigm allowed us to compare presaccadic visual discrimination performance at the endpoint of accurate saccades (landing at one of the saccade targets) and of averaging saccades (landing at an intermediate location in between the two targets). We observed a selective enhancement of visual sensitivity at the endpoint of accurate saccades but not at the endpoint of averaging saccades. Rather, before the execution of averaging saccades, visual sensitivity was equally enhanced at both targets, suggesting that saccade averaging follows from unresolved attentional selection among the saccade targets. These results argue against a mandatory coupling between visual attention and saccade programming based on a direct measure of presaccadic visual sensitivity rather than saccadic reaction times, which have been used in other protocols to draw similar conclusions. While our protocol provides a useful framework to investigate the relationship between visual attention and saccadic eye movements at the behavioral level, it can also be combined with electrophysiological measures to extend insights at the neuronal level.

This experimental protocol combined eye tracking and the assessment of presaccadic visual sensitivity in a dual task paradigm, consisting of a free choice saccade task and a visual discrimination task, to investigate the deployment of visual spatial attention before both, accurate and averaging saccades.

This experimental protocol was designed to investigate whether visual attention is obligatorily deployed at the endpoint of saccades. To this end, we ...

Defining the Role Of Language in Infants' Object Categorization with Eye-tracking Paradigms

Assessing infant category learning is a challenging but vital aspect of studying infant cognition. By employing a familiarization-test paradigm, we straightforwardly measure infants&#8217; success in learning a novel category while relying only on their looking behavior. Moreover, the paradigm can directly measure the impact of different auditory signals on the infant categorization across a range of ages. For instance, we assessed how 2-year-olds learn categories in a variety of labeling environments: in our task, 2-year-olds successfully learned categories when all exemplars were labeled&#160;or the first two exemplars were labeled, but they failed to categorize when no exemplars were labeled or only the final two exemplars were labeled. To determine infants&#8217; success in such tasks, researchers can examine both the overall preference displayed by infants in each condition and infants&#8217; pattern of looking over the course of the test phase, using an eye-tracker to provide fine-grained time-course data. Thus, we present a powerful paradigm for identifying the role of language, or any auditory signal, in infants&#8217; object category learning.

Here we present a protocol for familiarization-test paradigms which provide a direct test of infant categorization and help to define the role of language in early category learning.

Assessing infant category learning is a challenging but vital aspect of studying infant cognition. By employing a familiarization-test paradigm, we ...