Central and Divided Visual Field Presentation of Emotional Images to Measure Hemispheric Differences in Motivated Attention

Two dominant theories on lateralized processing of emotional information exist in the literature. One theory posits that unpleasant emotions are processed ...

University of Kansas

We examined hemispheric lateralization of emotion processing by comparing the performance of clinically depressed, previously depressed, and control individuals on a divided visual field task. Participants were asked to make affective valence judgments for each in a series of laterally presented person-descriptive adjectives. Study results suggest that the right cerebral hemisphere (RH) is preferentially sensitive to the affective context of language. Among targets presented to the RH, depressed and previously depressed participants were significantly faster and more accurate in their judgments of negative target words, while controls responded more quickly and accurately to positive target words. No such effects were observed for targets presented to the left hemisphere. It is hypothesized that affective sensitivity may result in differences in semantic network organization across individuals who vary in affective experience.

Hemispheric asymmetry in the processing of emotional content in word meanings: the effect of current and past depression.

Event-related potentials (ERPs) were used as the dependent measure in a divided visual field study examining the processing of lexically ambiguous words in the cerebral hemispheres. The goal was to determine if the N400 ERP component is sensitive measure of hemispheric differences in semantic processing. ERP waveforms were examined for lateralized target words that were related to either the dominant (MONEY) or subordinate (RIVER) meanings of ambiguous words (BANK). These waveforms were compared to trials where the prime-target pairs were unrelated. Reliable N400s, reflecting a significant difference between related and unrelated trials, were seen when targets were presented to the right visual field/left hemisphere. However, there were no N400s observed for either the dominant or subordinate conditions when targets were presented to the left visual field/right hemisphere.

Using event-related potentials to examine hemispheric differences in semantic processing.

The present study employs event related potentials (ERPs) to verify the utility of using electrophysiological measures to study developmental questions within the field of language comprehension. Established ERP components (N400 and P600) that reflect semantic and syntactic processing were examined. Fifteen adults and 14 children (ages 8-13) processed spoken stimuli containing either semantic or syntactic anomalies. Adult participants showed a significant N400 in response to semantic anomalies and P600 components in response to syntactic anomalies. Children also show evidence of both ERP components. The children's N400 component differed from the adults' in scalp location, latency, and component amplitude. The children's P600 was remarkably similar to the P600 shown by adults in scalp location, component amplitude, and component latency. Theoretical implication for theories of language comprehension in adults and children will be discussed.

A comparison of semantic and syntactic event related potentials generated by children and adults.

Language processing across the life span: new methodologies to study old questions.

A problem in divided visual field studies (especially those using event-related potentials as a dependent measure) is the large number of horizontal eye movements participants make during experimental trials. Past attention research suggests that eye movements to lateralised targets should be significantly reduced using a dynamic, offset mask, causing a reduction in attentional capture. The current study attempted to replicate past divided visual field language studies using offset masking procedures. Using a basic offset procedure, eye movements were not reduced in Experiment 1. However, Experiment 2 did show a significant reduction in eye movements using a new dynamic offset masking procedure. Low accuracy rates were a concern throughout. In conclusion, horizontal eye movements can be reduced with a dynamic offset procedure but the low accuracy rates and the inconsistent behavioural findings throughout the study suggest that further study and refinement of the paradigm is needed.

Offset masking in a divided visual field study.

A divided visual field (DVF) experiment examined the semantic processing strategies employed by the cerebral hemispheres to determine if strategies observed with written word stimuli generalize to other media for communicating semantic information. We employed picture stimuli and vary the degree of semantic relatedness between the picture pairs. Participants made an on-line semantic relatedness judgment in response to sequentially presented pictures. We found that when pictures are presented to the right hemisphere responses are generally more accurate than the left hemisphere for semantic relatedness judgments for picture pairs. Furthermore, consistent with earlier DVF studies employing words, we conclude that the RH is better at accessing or maintaining access to information that has a weak or more remote semantic relationship. We also found evidence of faster access for pictures presented to the LH in the strongly-related condition. Overall, these results are consistent with earlier DVF word studies that argue that the cerebral hemispheres each play an important and separable role during semantic retrieval.

Examining lateralized semantic access using pictures.

The individual roles played by the cerebral hemispheres during the process of language comprehension have been extensively studied in tasks that require individuals to read text (for review see Jung-Beeman, 2005). However, it is not clear whether or not some aspects of the theorized laterality models of semantic comprehension are a result of the modality of presentation. Extending earlier work examining lateralized semantic processing using lexically ambiguous words, the current experiments utilized two modified lexical-decision tasks (one fully auditory and one cross-modal) with dichotically presented target stimuli. When targets were presented to the right ear/left hemisphere there was a distinct advantage for detecting words that are associated with the dominant meaning of the ambiguous word over the subordinate meaning. In contrast, for left ear/right hemisphere trials, there was either no difference between the pattern of semantic access for dominant and subordinate meaning (dichotic only) or a processing advantage for the subordinate meaning of the ambiguous word (with cross-modal presentation). These data suggest that the complimentary hemispheric strategies that allow for semantic access are not modality specific and instead characterize how the hemispheres each contribute to comprehension for both speech and text. Thus, dichotic presentation does seem to allow for the study of subtle hemispheric difference in meaning comprehension.

Examining lateralized lexical ambiguity processing using dichotic and cross-modal tasks.

There is evidence of maladaptive attentional biases for lexical information (e.g., Atchley, Ilardi, & Enloe, 2003; Atchley, Stringer, Mathias, Ilardi, & Minatrea, 2007) and for pictographic stimuli (e.g., Gotlib, Krasnoperova, Yue, & Joormann, 2004) among patients with depression. The current research looks for depressotypic processing biases among depressed out-patients and non-clinical controls, using both verbal and pictorial stimuli. A d' measure (sensitivity index) was used to examine each participant's perceptual sensitivity threshold. Never-depressed controls evidenced a detection bias for positive picture stimuli, while depressed participants had no such bias. With verbal stimuli, depressed individuals showed specific decrements in the detection of positive person-referent words (WINNER), but not with positive non-person-referent words (SUNSHINE) or with negative words. Never-depressed participants showed no such differences across word types. In the current study, depression is characterised both by an absence of the normal positivistic biases seen in individuals without mood disorders (consistent with McCabe & Gotlib, 1995), and by a specific reduction in sensitivity for person-referent positive information that might be inconsistent with depressotypic self-schemas.

Depression reduces perceptual sensitivity for positive words and pictures.

Adults and children are spending more time interacting with media and technology and less time participating in activities in nature. This life-style change clearly has ramifications for our physical well-being, but what impact does this change have on cognition? Higher order cognitive functions including selective attention, problem solving, inhibition, and multi-tasking are all heavily utilized in our modern technology-rich society. Attention Restoration Theory (ART) suggests that exposure to nature can restore prefrontal cortex-mediated executive processes such as these. Consistent with ART, research indicates that exposure to natural settings seems to replenish some, lower-level modules of the executive attentional system. However, the impact of nature on higher-level tasks such as creative problem solving has not been explored. Here we show that four days of immersion in nature, and the corresponding disconnection from multi-media and technology, increases performance on a creativity, problem-solving task by a full 50% in a group of naive hikers. Our results demonstrate that there is a cognitive advantage to be realized if we spend time immersed in a natural setting. We anticipate that this advantage comes from an increase in exposure to natural stimuli that are both emotionally positive and low-arousing and a corresponding decrease in exposure to attention demanding technology, which regularly requires that we attend to sudden events, switch amongst tasks, maintain task goals, and inhibit irrelevant actions or cognitions. A limitation of the current research is the inability to determine if the effects are due to an increased exposure to nature, a decreased exposure to technology, or to other factors associated with spending three days immersed in nature.

Creativity in the wild: improving creative reasoning through immersion in natural settings.

Two experiments were conducted to determine if the right hemisphere (RH) plays a central role in understanding sarcasm. In Experiment 1, 48 participants completed a target detection task using dichotically presented phrases that were sincere (message compatible), sarcastic (conflicting semantic and prosodic message), or neutral (no emotional prosody). Sarcastic phrases presented to the left ear (LE)/RH produced faster response times than sarcastic phrases presented to the right ear/left hemisphere. Accuracy results indicated an overall LE/RH advantage for detecting both sarcastic and sincere phrases. Experiment 2 utilized the same task with the addition of event-related potential recording. There was a reliable N400 seen in response to the sarcastic phrases, but only with LE/RH presentation. These results suggest that the RH is particularly sensitive to the mismatch between semantic and prosodic information characterized by sarcasm.

Detection of sarcastic speech: The role of the right hemisphere in ambiguity resolution.

The goal of the present study was to explore how anger reduction via a single session of meditation might be measured using psychophysiological methodologies. To achieve this, 15 novice meditators (Experiment 1) and 12 practiced meditators (Experiment 2) completed autobiographical anger inductions prior to, and following, meditation training while respiration rate, heart rate, and blood pressure were measured. Participants also reported subjective anger via a visual analog scale. At both stages, the experienced meditators' physiological reaction to the anger induction reflected that of relaxation: slowed breathing and heart rate and decreased blood pressure. Naïve meditators exhibited physiological reactions that were consistent with anger during the pre-meditation stage, while after meditation training and a second anger induction they elicited physiological evidence of relaxation. The current results examining meditation training show that the naïve group's physiological measures mimicked those of the experienced group following a single session of meditation training.

A single session of meditation reduces of physiological indices of anger in both experienced and novice meditators.

Anterior cingulate cortex (ACC) and striatum are part of the emotional neural circuitry implicated in major depressive disorder (MDD). Music is often used for emotion regulation, and pleasurable music listening activates the dopaminergic system in the brain, including the ACC. The present study uses functional MRI (fMRI) and an emotional nonmusical and musical stimuli paradigm to examine how neural processing of emotionally provocative auditory stimuli is altered within the ACC and striatum in depression.

Neural Processing of Emotional Musical and Nonmusical Stimuli in Depression.

The motivated attention network is believed to be the system that allocates attention toward motivationally relevant, emotional stimuli in order to better prepare an organism for action [Lang, P. J., Bradley, M. M., & Cuthbert, B. N. (1997). Motivated attention: Affect, activation, and action. In P. J. Lang, R. F. Simons, M. Balaban, & R. Simons (Eds.), Attention and orienting: Sensory and motivational processes (pp. 97-135). Psychology Press]. The late positive potential (LPP), an event-related potential (ERP) that is a manifestation of the motivated attention network, has not been found to reliably differentiate the valence of emotionally relevant stimuli. In two studies, we systematically varied epoch, stimulus arousal, stimulus valence, and hemisphere of presentation (Study 2) to investigate valence effects in the LPP. Both central and divided visual field presentations of emotional stimuli found the LPP to be sustained in later windows for high-arousing unpleasant images compared to pleasant images. Further, this effect was driven by sustained LPP responses following left hemisphere presentations of unpleasant stimuli compared to right. Findings are discussed regarding hemispheric processing of emotion and how lateralized emotion processes might contribute to psychopathology.

Valence and arousal influence the late positive potential during central and lateralized presentation of images.

Previous research has found that more embodied insults (e.g. numbskull) are identified faster and more accurately than less embodied insults (e.g. idiot). The linguistic processing of embodied compliments has not been well explored. In the present study, participants completed two tasks where they identified insults and compliments, respectively. Half of the stimuli were more embodied than the other half. We examined the late positive potential (LPP) component of event-related potentials in early (400-500 ms), middle (500-600 ms), and late (600-700 ms) time windows. Increased embodiment resulted in improved response accuracy to compliments in both tasks, whereas it only improved accuracy for insults in the compliment detection task. More embodied stimuli elicited a larger LPP than less embodied stimuli in the early time window. Insults generated a larger LPP in the late time window in the insult task; compliments generated a larger LPP in the early window in the compliment task. These results indicate that electrophysiological correlates of emotional language perception are sensitive to both top-down and bottom-up processes.

Ruth Ann Atchley

Department of Psychology

University of Kansas

Central and Divided Visual Field Presentation of Emotional Images to Measure Hemispheric Differences in Motivated Attention

Ruth Ann Atchley

.css-o250i3{font-size:18px;font-family:Open Sans,sans-serif;line-height:21.6px;}Department of Psychology

University of Kansas

Central and Divided Visual Field Presentation of Emotional Images to Measure Hemispheric Differences in Motivated Attention

Department of Psychology