Monday, February 28, 2005

ARTICLE UPDATE - Emotional content and reality-monitoring ability: fMRI evidence for the influences of encoding processes

Elizabeth A. Kensinger, and Daniel L. Schacter

Neuropsychologia, in press

Memory for emotional items can be less prone to some types of memory distortion, such as reality-monitoring errors, than memory for neutral items. The present fMRI study examined whether this enhanced reality-monitoring accuracy reflects engagement of distinct processes recruited during encoding of emotional information. Participants only imagined named objects (word-only trials) or imagined named objects and then also viewed photos of them (word-picture trials). Half of the items were emotional (e.g., snake, casket). Later, participants heard object names and indicated whether the corresponding photo had been shown. Reality-monitoring errors occurred when participants attributed an item from a word-only trial to a word-picture trial. Such misattribution errors occurred less frequently for emotional than neutral items. Activity in emotion-processing regions (e.g., orbitofrontal cortex, amygdala) reduced the likelihood of later misattributions, likely due in part to interactions with regions that promote memory accuracy (e.g., the hippocampus). Distinct neural processes also increased the likelihood of reality-monitoring errors, depending on the emotional content of the items. Activity spanning the fusiform and parahippocampal gyri (likely reflecting mental imagery) increased the likelihood of reality-monitoring errors for neutral items, while activity in the anterior cingulate increased the likelihood of reality-monitoring errors for emotional items.

Tuesday, February 22, 2005

Smiles don't lie

Study claims you can tell a person's nationality by their smile

Read the article in English

Wednesday, February 16, 2005

Late news

December issue of Journal of Cognitive Neuroscience is a special issue about social cognitive neuroscience and there are a lot of research related to emotion. Take a look.

Tuesday, February 15, 2005

ARTICLE UPDATE - Remembering one year later: Role of the amygdala and the medial temporal lobe memory system in retrieving emotional memories

Florin Dolcos, Kevin S. LaBar and Roberto Cabeza

PNAS | February 15, 2005 | vol. 102 | no. 7 | 2626-2631

The memory-enhancing effect of emotion can be powerful and long-lasting. Most studies investigating the neural bases of this phenomenon have focused on encoding and early consolidation processes, and hence little is known regarding the contribution of retrieval processes, particularly after lengthy retention intervals. To address this issue, we used event-related functional MRI to measure neural activity during the retrieval of emotional and neutral pictures after a retention interval of 1 yr. Retrieval activity for emotional and neutral pictures was separately analyzed for successfully (hits) vs. unsuccessfully (misses) retrieved items and for responses based on recollection vs. familiarity. Recognition performance was better for emotional than for neutral pictures, and this effect was found only for recollection-based responses. Successful retrieval of emotional pictures elicited greater activity than successful retrieval of neutral pictures in the amygdala, entorhinal cortex, and hippocampus. Moreover, in the amygdala and hippocampus, the emotion effect was greater for recollection than for familiarity, whereas in the entorhinal cortex, it was similar for both forms of retrieval. These findings clarify the role of the amygdala and the medial temporal lobe memory regions in recollection and familiarity of emotional memory after lengthy retention intervals.

ARTICLE UPDATE - The human orbitofrontal cortex monitors outcomes even when no reward is at stake

Armin Schnider, Valerie Treyer and Alfred Buck

Neuropsychologia, 43, 316-323

The orbitofrontal cortex (OFC) processes the occurrence or omission of anticipated rewards, but clinical evidence suggests that it might serve as a generic outcome monitoring system, independent of tangible reward. In this positron emission tomography (PET) study, normal human subjects performed a series of tasks in which they simply had to predict behind which one of two colored rectangles a drawing of an object was hidden. While all tasks involved anticipation in that they had an expectation phase between the subject’s prediction and the presentation of the outcome, they varied with regards to the uncertainty of outcome. No comment on the correctness of the prediction, no record of ongoing performance, and no reward, not even a score, was provided. Nonetheless, we found strong activation of the OFC: in comparison with a baseline task, the left anterior medial OFC showed activation in all conditions, indicating a basic role in anticipation; the left posterior OFC was activated in all tasks with some uncertainty of outcome, suggesting a role in the monitoring of outcomes; the right medial OFC showed activation exclusively during guessing. The data indicate a generic role of the human OFC, with some topical specificity, in the generation of hypotheses and processing of outcomes, independent of the presence of explicit reward.

Saturday, February 12, 2005

ARTICLE UPDATE - Interactions between the processing of gaze direction and facial expression

Tzvi Ganel, Yonatan Goshen-Gottstein and Melvyn A. Goodale

Vision Research, 45, 1191-1200

In this article, we explored the relationship between the processing of facial expression and the processing of gaze direction. In Experiment 1, participants were unable to ignore gaze while classifying expression—or to ignore expression while classifying gaze. This suggests that the processing of expression and the processing of gaze are interdependent. In Experiment 2, the faces were inverted to isolate configural from part-based contributions to this interdependence. Inversion had a striking effect on expression judgments, which could now be processed independently of gaze, but not on gaze judgments, which were still influenced by expression, even when photos that contained only the eye region of faces were presented (Experiment 4). In Experiment 3 the processing of expression was found to be sensitive to even small variations in the direction of gaze. These results suggest that the processing underlying judgments of expression is configural and entails an obligatory computation of gaze direction. Judgments of gaze direction, however, are carried out in a part-based manner using local features around the eyes and are insensitive to the configural aspects of facial processing.

Friday, February 11, 2005

ARTICLE UPDATE - Behavioral and Electrophysiological Evidence of a Right Hemisphere Bias for the Influence of Negative Emotion on Higher Cognition

Emiliana R. Simon-Thomas, Kemi O. Role and Robert T. Knight

Journal of Cognitive Neuroscience, 17, 518-529

We examined how responses to aversive pictures affected performance and stimulus-locked event-related potentials (ERPs) recorded during a demanding cognitive task. Numeric Stroop stimuli were briefly presented to either left or right visual hemifield (LVF and RVF, respectively) after a centrally presented aversive or neutral picture from the International Affective Picture System. Subjects indicated whether a quantity value from each Stroop stimulus matched the preceding Stroop stimulus while passively viewing the pictures. After aversive pictures, responses were more accurate for LVF Stroops and less accurate for RVF Stroops. Early-latency extrastriate attention-dependent visual ERPs were enhanced for LVF Stroops. The N2 ERP was enhanced for LVF Stroops over the right frontal and parietal scalp sites. Slow potentials (300–800 msec) recorded over the frontal and parietal regions showed enhanced picture related modulation and amplitude for LVF Stroops. These results suggest that emotional responses to aversive pictures selectively facilitated right hemisphere processing during higher cognitive task performance.

Wednesday, February 09, 2005

A note about mirror site

Because the previous server isn't very stable. I've decided to move stuff to another place and here it is. From now on, the articles will appear on both sites. I'll add the linkages later on. I think it's a waste of time to move all the stuff from Emotion Rules so if you're interested in previous posts, please go there and take a look.

BTW, if you'd like to become a contributor please do let me know. Thanks