Limor Lichtenstein-Vidne

Dynamic modulation of emotional processing

Recent findings suggest the processing of emotional stimuli is prioritized compared to neutral stimuli; however, it is not necessarily automatic and depends on several modulating factors. The current paper highlights three major factors that affect the reactions to emotional stimuli: (i) stimulus properties, (ii) task demands and attention, and (iii) individual characteristics. The evidence reviewed here suggests that individual characteristics shape the structure, function and connectivity within a neural network that is involved in the reactions to emotional stimuli. This neural network includes regions related to emotion and attention, in line with evidence for reciprocal connections between these two processes. Activation in this network further depends on the emotional value of a certain item, as well as physical features of the stimulus. This integrative view can lead to better understanding of the underlying mechanisms of emotional reactions, as well as better therapeutic approaches.

Task relevance modulates processing of distracting emotional stimuli

Numerous studies have claimed that emotional stimuli are able to capture attention automatically when presented outside the main focus of attention. In the current study this claim was tested by using task-relevant and task-irrelevant emotional stimuli. Specifically, in two experiments the effect of emotional stimuli presented in the periphery of attention was tested by using a flanker task. Results showed that emotional stimuli did not capture attention in an unconditional manner. Emotional distracting stimuli created interference only when they were relevant to the task. The findings suggest that “task relevance” is determined by (a) task requirements, and/or (b) target characteristics. The current results have implications for the concept of cognitive load and automaticity of processing emotional stimuli.

Task-Relevance Modulates the Effects of Peripheral Distractors

The current study investigated whether task-relevant information affects performance differently from how information that is not relevant for the task does when presented peripherally and centrally. In three experiments a target appeared inside the focus of attention, whereas a to-be-ignored distractor appeared either in the periphery (Experiments 1 and 2) or at the centre (Experiment 3) of attention. In each trial the distractor carried both task-relevant and irrelevant information. The results confirmed the “task relevance” hypothesis: Task-irrelevant information affected performance only when it appeared at the centre of attention, whereas task-relevant information affected performance when it appeared inside as well as outside the main focus of attention. The current results do not support suggestions that spatial stimuli (e.g., arrows) draw attention automatically regardless of task relevance.

Explicit vs. implicit emotional processing: The interaction between processing type and executive control

The current study examined whether the interaction between emotion and executive control (EC) is modulated by the processing type of the emotional information. Namely, whether the emotional information is explicitly processed, implicitly processed or passively viewed. In each trial, a negative or neutral picture preceded an arrow-flanker stimulus that was congruent or incongruent. Incongruent stimuli are known to recruit EC. Explicit processing of the pictures (Experiment 1a), which required responding to their emotional content, resulted in emotional interference for congruent but not for incongruent stimuli. Similar effects were shown for the passive viewing condition (Experiment 2). In contrast, implicit processing (Experiment 1b), which required responding to non-emotional content, resulted in emotional interference for both congruent and incongruent stimuli. Thus, our findings indicate that implicit emotional processing affects performance independently of EC recruitment. In contrast, explicit emotional processing and passive viewing of emotional pictures lead to reduced emotional interference when EC is recruited.

Attentional bias in clinical depression and anxiety: The impact of emotional and non-emotional distracting information

Both anxiety and major depression disorder (MDD) were reported to involve a maladaptive selective attention mechanism, associated with bias toward negative stimuli. Previous studies investigated attentional bias using distractors that required processing as part of task settings, and therefore, in our view, these distractors should be regarded as task-relevant. Here, we applied a unique task that used peripheral distractors that presented emotional and spatial information simultaneously. Notably, the emotional information was not associated in any way to the task, and thus was task-irrelevant. The spatial information, however, was task-relevant as it corresponded with task instructions. Corroborating previous findings, anxious patients showed attentional bias toward negative information. MDD patients showed no indication of this bias. Spatial information influenced all groups similarly. These results indicate that anxiety, but not MDD, is associated with an inherent negative information bias, further illustrating that the two closely related disorders are characterized by different processing patterns.

Attentional bias in anxiety and depression: The impact of emotional and non-emotional distracting information

Both anxiety and major depression disorder (MDD) were reported to involve a maladaptive selective attention mechanism, associated with bias toward negative stimuli. Previous studies investigated attentional bias using distractors that required processing as part of task settings, and therefore, in our view, these distractors should be regarded as task-relevant. Here, we applied a unique task that used peripheral distractors that presented emotional and spatial information simultaneously. Notably, the emotional information was not associated in any way to the task, and thus was task-irrelevant. The spatial information, however, was task-relevant as it corresponded with task instructions. Corroborating previous findings, anxious patients showed attentional bias toward negative information. MDD patients showed no indication of this bias. Spatial information influenced all groups similarly. These results indicate that anxiety, but not MDD, is associated with an inherent negative information bias, further illustrating that the two closely related disorders are characterized by different processing patterns.

Investigating Thought Disorder in Schizophrenia: Evidence for Pathological Activation

Background Previous research has yielded evidence for enhanced semantic priming in formal thought-disordered schizophrenia patients, a result that fits well with the hypothesis of disinhibited processes of spreading activation in this population. Objective The current study examined whether hyper priming among schizophrenia patients is an outcome of further spreading of activation of a node or a result of farther activation of nodes in the semantic network. We also try to shed light on the fate of this activation. Methods The present study tested this hypothesis by using semantic and identical priming in two different experiments. SOA (stimulus onset asynchrony) was manipulated (240 ms vs. 740 ms) within block. It is assumed that among healthy individuals, performance relies on a balance between activation and inhibition processes, contrary to in schizophrenic individuals. In order to examine this hypothesis, we compared formal thought-disordered schizophrenia patients, non thought-disordered schizophrenia patients, and healthy controls. Results For thought-disordered schizophrenia patients, we found a large positive semantic effect and identical priming effect (129 ms and 154 ms, respectively) only with short SOA. SOA and type of priming did not modulate priming effects in the control groups. Conclusions This result supports the claim that there is a lack of inhibitory processes among thought-disordered patients. Hyper priming in the thought-disorder group may be an outcome of hyper activation followed by rapid decay below baseline threshold.

Lateralisation of emotions: evidence from pupil size measurement

ABSTRACT The way our brain processes emotional stimuli has been studied intensively. One of the main issues still under debate is the laterality of valence processing. Herein, we employed the fact that pupil size increases under conditions of higher mental effort and during emotional processing, in order to contrast three proposed hypotheses in the field. We used different manual response mapping for emotional stimuli: Participants responded with their right hand for positive and with their left hand for negative facial expressions, or vice versa. The hands position was either regular (Experiment 1) or crossed (Experiment 2) in order to rule out a “spatial-valence association” alternate explanation. A third experiment was conducted by employing a passive viewing procedure of peripheral emotional stimuli. In the first two experiments, pupil size was larger when participants responded to positive stimuli with their left hand and to negative with their right hand, compared with the opposite mapping. Results of Experiment 3 strengthen the findings of Experiments 1 and 2. These findings provide significant psychophysiological evidence for the valence hypothesis: Processing positive stimuli involves the left hemisphere, while processing negative stimuli involves the right hemisphere. These results are discussed in relation to contemporary theories of emotion processing.

Flanking magnitudes: dissociation between numerosity and numerical value in a selective attention task.

The current research examined whether peripherally presented numerical information can affect the speed of number processing. In 2 experiments, participants were presented with a target matrix flanked by a distractor matrix and were asked to perform a comparative judgment (i.e., decide whether the target was larger or smaller than the reference 5). In Experiment 1, the target was symbolic (i.e., a single digit), and in Experiment 2, it was nonsymbolic (i.e., a random presentation of dots). In both experiments, flanker matrices had 2 dimensions-numerosity and numerical value-that were manipulated orthogonally to create stimulus congruent and stimulus incongruent conditions. Incongruent trials differed in the laterality between target and flanker (i.e., their location in relation to the reference 5). When responding to symbolic targets (Experiment 1), only the flankers numerical value affected reaction times (RTs), whereas when responding to nonsymbolic targets (Experiment 2), only the flankers numerosity affected RTs. In addition, the pattern of flanker interference differed between targets: For symbolic targets, laterality did not affect responses, whereas for nonsymbolic targets, laterality did affect responses. These results imply both symbolic and nonsymbolic magnitudes can be automatically activated; however, this activation is contingent upon their relevance to the task at hand. Implications of these results on the efficiency of the visual processing system and on numerical cognition are further discussed.