Olivers CN, Nieuwenhuis S.
Journal of Experimental Psychology: Human Perception & Performances, 32, 364-379
The attentional blink reflects the impaired ability to identify the 2nd of 2 targets presented in close succession--a phenomenon that is generally thought to reflect a fundamental cognitive limitation. However, the fundamental nature of this impairment has recently been called into question by the counterintuitive finding that task-irrelevant mental activity improves attentional blink performance (C. N. L. Olivers & S. Nieuwenhuis, 2005). The present study found a reduced attentional blink when participants concurrently performed an additional memory task, viewed pictures of positive affective content, or were instructed to focus less on the task. These findings support the hypothesis that the attentional blink is due to an overinvestment of attentional resources in stimulus processing, a suboptimal processing mode that can be counteracted by manipulations promoting divided attention.
*Note that their results published in 2005 has been questioned
Friday, April 28, 2006
ARTICLE UPDATE - The impact of emotion on perception: bias or enhanced processing?
Zeelenberg R, Wagenmakers EJ, Rotteveel M.
Psychological Science, 17, 287-291
Recent studies have shown that emotionally significant stimuli are often better identified than neutral stimuli. It is not clear, however, whether these results are due to enhanced perceptual processing or to a bias favoring the identification of emotionally significant stimuli over neutral stimuli. The present study used a two-alternative forced-choice perceptual identification task to disentangle the effects of bias and enhanced processing. We found that emotionally significant targets were better identified than neutral targets. In contrast, the emotional significance of the foil alternative had no effect on performance. The present results support the hypothesis that perceptual encoding of emotionally significant stimuli is enhanced.
Psychological Science, 17, 287-291
Recent studies have shown that emotionally significant stimuli are often better identified than neutral stimuli. It is not clear, however, whether these results are due to enhanced perceptual processing or to a bias favoring the identification of emotionally significant stimuli over neutral stimuli. The present study used a two-alternative forced-choice perceptual identification task to disentangle the effects of bias and enhanced processing. We found that emotionally significant targets were better identified than neutral targets. In contrast, the emotional significance of the foil alternative had no effect on performance. The present results support the hypothesis that perceptual encoding of emotionally significant stimuli is enhanced.
ARTICLE UPDATE - Emotion facilitates perception and potentiates the perceptual benefits of attention.
Phelps EA, Ling S, Carrasco M.
Psychological Science, 17, 292-299.
Does emotion affect how people see? We investigated the effects of emotion and attention, as well as their conjoint effect, on contrast sensitivity, a dimension of early vision. We manipulated the emotional valence and the attentional distribution of cues preceding a target stimulus and asked observers to judge the orientation of the target as contrast varied. This study provides the first behavioral evidence that (a) emotion enhances contrast sensitivity irrespective of attention and (b) emotion potentiates the effect of attention on contrast sensitivity.
Psychological Science, 17, 292-299.
Does emotion affect how people see? We investigated the effects of emotion and attention, as well as their conjoint effect, on contrast sensitivity, a dimension of early vision. We manipulated the emotional valence and the attentional distribution of cues preceding a target stimulus and asked observers to judge the orientation of the target as contrast varied. This study provides the first behavioral evidence that (a) emotion enhances contrast sensitivity irrespective of attention and (b) emotion potentiates the effect of attention on contrast sensitivity.
ARTICLE UPDATE - Emotional category data on images from the International Affective Picture System.
Mikels JA, Fredrickson BL, Larkin GR, Lindberg CM, Maglio SJ, Reuter-Lorenz PA.
Behavioural Research Methods, 37, 626-630
The International Affective Picture System (IAPS) is widely used in studies of emotion and has been characterized primarily along the dimensions of valence, arousal, and dominance. Even though research has shown that the IAPS is useful in the study of discrete emotions, the categorical structure of the IAPS has not been characterized thoroughly. The purpose of the present project was to collect descriptive emotional category data on subsets of the LAPS in an effort to identify images that elicit onediscrete emotion more than others. These data reveal multiple emotional categories for the images and indicate that this image set has great potential in the investigation of discrete emotions. This article makes these data available to researchers with such interests. Data for all the pictures are archived at www.psychonomic.org/archive/. (not available on line yet)
Behavioural Research Methods, 37, 626-630
The International Affective Picture System (IAPS) is widely used in studies of emotion and has been characterized primarily along the dimensions of valence, arousal, and dominance. Even though research has shown that the IAPS is useful in the study of discrete emotions, the categorical structure of the IAPS has not been characterized thoroughly. The purpose of the present project was to collect descriptive emotional category data on subsets of the LAPS in an effort to identify images that elicit onediscrete emotion more than others. These data reveal multiple emotional categories for the images and indicate that this image set has great potential in the investigation of discrete emotions. This article makes these data available to researchers with such interests. Data for all the pictures are archived at www.psychonomic.org/archive/. (not available on line yet)
Monday, April 24, 2006
ARTICLE UPDATE - Attention does not modulate neural responses to social stimuli in autism spectrum disorders
Geoffrey Bird, Caroline Catmur, Giorgia Silani, Chris Frith and Uta Frith
NeuroImage, in press
We investigated whether individuals with autism spectrum disorders (ASD) would show attentional modulation for social (face) and non-social (house) stimuli. Sixteen individuals with ASD and 16 matched control participants completed a task in which pairs of face and house stimuli were present on every trial, with one of the pairs randomly assigned to attended locations and the other to unattended locations. Both mass-univariate (SPM) and region of interest analyses suggested that responses to houses were modulated by attention in both groups, but that only the control participants demonstrated attentional modulation of face-selective regions. Thus, the participants with ASD demonstrated a lack of attentional modulation which was particularly evident for the social stimulus. Analyses of effective connectivity indicated that these results were due to a failure of attention to modulate connectivity between extrastriate areas and V1. We discuss how these results may suggest a mechanism to explain the reduced salience of social stimuli in ASD.
NeuroImage, in press
We investigated whether individuals with autism spectrum disorders (ASD) would show attentional modulation for social (face) and non-social (house) stimuli. Sixteen individuals with ASD and 16 matched control participants completed a task in which pairs of face and house stimuli were present on every trial, with one of the pairs randomly assigned to attended locations and the other to unattended locations. Both mass-univariate (SPM) and region of interest analyses suggested that responses to houses were modulated by attention in both groups, but that only the control participants demonstrated attentional modulation of face-selective regions. Thus, the participants with ASD demonstrated a lack of attentional modulation which was particularly evident for the social stimulus. Analyses of effective connectivity indicated that these results were due to a failure of attention to modulate connectivity between extrastriate areas and V1. We discuss how these results may suggest a mechanism to explain the reduced salience of social stimuli in ASD.
Thursday, April 20, 2006
ARTICLE UPDATE - Non-conscious recognition of emotional body language.
de Gelder B, Hadjikhani N.
Neuroreport, 17, 583-586
Patients with cortical blindness can reliably perceive some facial expressions even if they are unaware of their percept. We examined whether emotional body language may also be recognized in the absence of the primary visual cortex and without conscious stimulus perception. We presented emotional and neutral body images in the blind field of a patient with unilateral striate cortex damage. Using functional magnetic resonance imaging, we measured activation following presentation to the blind hemifield of whole body images (happy, neutral) with the face blurred. Unseen happy body images selectively activated area MT and the pulvinar nucleus of the thalamus, while unseen instrumental neutral body images activated the premotor cortex. Our results show that in the absence of the striate cortex implicit bodily emotion perception may be possible.
Neuroreport, 17, 583-586
Patients with cortical blindness can reliably perceive some facial expressions even if they are unaware of their percept. We examined whether emotional body language may also be recognized in the absence of the primary visual cortex and without conscious stimulus perception. We presented emotional and neutral body images in the blind field of a patient with unilateral striate cortex damage. Using functional magnetic resonance imaging, we measured activation following presentation to the blind hemifield of whole body images (happy, neutral) with the face blurred. Unseen happy body images selectively activated area MT and the pulvinar nucleus of the thalamus, while unseen instrumental neutral body images activated the premotor cortex. Our results show that in the absence of the striate cortex implicit bodily emotion perception may be possible.
ARTICLE UPDATE - Emotional information processing in mood disorders: a review of behavioral and neuroimaging findings.
Leppanen JM.
Current Opinions in Psychiatry, 19, 34-39.
A relatively long history of research has shown that mood disorders are associated with abnormalities in the processing of emotional stimuli. Only the most recent studies, however, have begun to elucidate the specificity and neural basis of these abnormalities. This article reviews and discusses the results of these studies. RECENT FINDINGS: Individuals diagnosed with major depressive disorder exhibit an attentional bias toward negative emotional cues (e.g. sad faces), an attentional bias away from positive emotional cues (e.g. happy faces), and an enhanced memory for negative emotional material. Compared with healthy controls, individuals with major depressive disorder show increased neural activity in response to sad faces and diminished neural activity in response to happy faces in emotion-related brain circuits (e.g. amygdala and ventral striatum). Some of these abnormalities in the processing of emotional information persist after symptom remission and they have also been found in healthy individuals who are at heightened risk for the development of mood disorders. SUMMARY: The reviewed data show that major depressive disorder involves specific abnormalities in the cognitive and neural processing of emotional information and that these abnormalities may potentially contribute to the vulnerability for negative emotion and onset of depressive episodes.
Current Opinions in Psychiatry, 19, 34-39.
A relatively long history of research has shown that mood disorders are associated with abnormalities in the processing of emotional stimuli. Only the most recent studies, however, have begun to elucidate the specificity and neural basis of these abnormalities. This article reviews and discusses the results of these studies. RECENT FINDINGS: Individuals diagnosed with major depressive disorder exhibit an attentional bias toward negative emotional cues (e.g. sad faces), an attentional bias away from positive emotional cues (e.g. happy faces), and an enhanced memory for negative emotional material. Compared with healthy controls, individuals with major depressive disorder show increased neural activity in response to sad faces and diminished neural activity in response to happy faces in emotion-related brain circuits (e.g. amygdala and ventral striatum). Some of these abnormalities in the processing of emotional information persist after symptom remission and they have also been found in healthy individuals who are at heightened risk for the development of mood disorders. SUMMARY: The reviewed data show that major depressive disorder involves specific abnormalities in the cognitive and neural processing of emotional information and that these abnormalities may potentially contribute to the vulnerability for negative emotion and onset of depressive episodes.
Monday, April 03, 2006
ARTICLE UPDATE - They know the words, but not the music: Affective and semantic priming in individuals with psychopathy.
Blair KS, Richell RA, Mitchell DG, Leonard A, Morton J, Blair RJ.
Biological Psychology, in press
Previous work has indicated dysfunctional affect-language interactions in individuals with psychopathy through use of the lexical decision task. However, it has been uncertain as to whether these deficits actually reflect impaired affect-language interactions or a more fundamental deficit in general semantic processing. In this study, we examined affective priming and semantic priming (dependent measures were reaction times and error rates) in individuals with psychopathy and comparison individuals, classified according to the psychopathy checklist revised (PCL-R) [Hare, R.D., 1991. The Hare Psychopathy Checklist-Revised. Multi-Health Systems, Toronto, Ont.]. Individuals with psychopathy showed significantly less affective priming relative to comparison individuals. In contrast, the two groups showed comparable levels of semantic priming. The results are discussed with reference to current models of psychopathy.
Biological Psychology, in press
Previous work has indicated dysfunctional affect-language interactions in individuals with psychopathy through use of the lexical decision task. However, it has been uncertain as to whether these deficits actually reflect impaired affect-language interactions or a more fundamental deficit in general semantic processing. In this study, we examined affective priming and semantic priming (dependent measures were reaction times and error rates) in individuals with psychopathy and comparison individuals, classified according to the psychopathy checklist revised (PCL-R) [Hare, R.D., 1991. The Hare Psychopathy Checklist-Revised. Multi-Health Systems, Toronto, Ont.]. Individuals with psychopathy showed significantly less affective priming relative to comparison individuals. In contrast, the two groups showed comparable levels of semantic priming. The results are discussed with reference to current models of psychopathy.
ARTICLE UPDATE- Increased positive emotional memory after repetitive transcranial magnetic stimulation over the orbitofrontal cortex
Schutter DJ, van Honk J.
Journal of Psychiatry Neuroscience, 31, 101-104.
Several studies have demonstrated increased left orbitofrontal cortex (OFC) activity during negative and depressed mood. These mood states have also been associated with reduced memory for positive emotional stimuli. The aim of the present study was to investigate whether slow, inhibitory repetitive transcranial magnetic stimulation (rTMS) over the left OFC would improve memory for positive material. METHODS: We carried out a study with a double-blind, within-subjects design, in which 12 healthy volunteers received 20 minutes of slow rTMS over the left OFC, placebo treatment over the left OFC and rTMS over the left dorsolateral portion of the prefrontal cortex. Effects on memory for fearful and happy faces were investigated. RESULTS: Memory for happy faces was significantly improved after rTMS over the left OFC compared with placebo (t(10) = 2.4, p = 0.037). CONCLUSIONS: These findings suggest a role of the OFC in positive emotional memory, which is in accordance with neuroimaging and neuropsychological data. It may be argued that dense projections from the OFC to the limbic emotional circuit are involved in emotional memory and, therefore, play a role in the effects of rTMS that we observed.
Journal of Psychiatry Neuroscience, 31, 101-104.
Several studies have demonstrated increased left orbitofrontal cortex (OFC) activity during negative and depressed mood. These mood states have also been associated with reduced memory for positive emotional stimuli. The aim of the present study was to investigate whether slow, inhibitory repetitive transcranial magnetic stimulation (rTMS) over the left OFC would improve memory for positive material. METHODS: We carried out a study with a double-blind, within-subjects design, in which 12 healthy volunteers received 20 minutes of slow rTMS over the left OFC, placebo treatment over the left OFC and rTMS over the left dorsolateral portion of the prefrontal cortex. Effects on memory for fearful and happy faces were investigated. RESULTS: Memory for happy faces was significantly improved after rTMS over the left OFC compared with placebo (t(10) = 2.4, p = 0.037). CONCLUSIONS: These findings suggest a role of the OFC in positive emotional memory, which is in accordance with neuroimaging and neuropsychological data. It may be argued that dense projections from the OFC to the limbic emotional circuit are involved in emotional memory and, therefore, play a role in the effects of rTMS that we observed.
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