Ms. Sarisa Boripet 55810263

a r t i c l e i n f o a b s t r a c tArticle history:Received : 26 October 2010Revised : 15 February 2011Accepted : 17 February 2011Available online : 22 February 2011Keywords : Facial expressions Emotion Working memory fMRI Facial

PURPOSE

using the n-back task to compare neuralresponses during

- an emotional expression WM task - a face identity WM task.

METHODS

- 20 undergraduates (9 female; 18–23 years old, mean age=19.2)

normalno psychiatric medicationreported no significant

neurologicalno psychiatric history

Participants

- informed consent approved by Dartmouth College Committee for the Protection of Human Subjects.- 2 participants were removed

METHODS

- All tasks were performed while participants were in the scanner.

Procedure

- Pilot data

15 participants performed a 2-back 15 participants performed a 3-back

task

EMO

ID

mean accuracy difference=7%

mean accuracy=70%

(mean accuracy=77%mean accuracy difference=11%

METHODS

- Each participant had two runs of 16 practice trials

Procedure

4 SHAPES

First practice run Shape of the image

second practice runcolor of the image

four alternating blocks of EMO and ID trials.

using the n-back task to compare neuralresponses during - an emotional expression WM task - a face identity WM task.

Selected images of four identities - 2 female - 2 male

The NimStim standardized

facial expression

stimulus set

METHODSProcedure

four emotional expressions

- for a total of 16 facesRandomly presented

presented once per block for 2000 ms

followed by a fixation cross that appeared for 500 ms

METHODSProcedure

METHODSProcedure

METHODSBehavioral data analysis

As has been previously described (Wilcox, 1992; Bush et al., 1993), trimming is an effective technique for dealing with outliers.

Therefore, we chose to trim trials for each subject according to a typical trimming threshold of the top 10% and bottom 10% reaction time (RT) values.

http://www.youtube.com/attribution_link?a=0oFh2Rk3cYo&u=%2Fwatch%3Fv%3DL3RkDChaWgU%26feature%3Dshare

METHODSImage acquisition

All subjects were scanned on a 3.0 Tesla Philips Intera Achieva Scanner

Visual stimuli were generated with a Dell laptop computer running E-Prime software

Epson (Model ELP-7000) LCD projector

METHODS

Imaging data analysis

Preprocessing and the general linear model

The fMRI data were analyzed using Statistical Parametric Mapping software (SPM2, Wellcome Department of Imaging Neuroscience, London, UK).None of the subjects had head movement more than 1.5 mm using the Montreal Neurological Institute (MNI)-152 template.

METHODS

Imaging data analysis

Between subjects correlations

predicted that dorsolateral prefrontal cortex (DLPFC) activity would correlate with amygdala EMO

taskwith invariant processing regions (lateral fusiform) during the ID task

ID task

RESULTS

Behavioral results

Accuracy

A task (emotion, identity)×trial (target, non-target) repeated measures ANOVA for accuracy revealed a significant main effect of task (F(1,17)=25.57, p < 0.001),Participants were significantly more accurate for the identity task than the emotion task (p < 0.001).significant task × trial interaction (F(1,17)=5.08, p<0.04)

mean ± standard error: targets: EMO=87.2% ± 2.2, ID=95.3%±1.5; non-targets: EMO=90.9%±1.3,ID=94.4%±1.6;

RESULTS

Behavioral results

Accuracy

Fig. 2. Behavioral results. Behavioral performance (mean±standard error) on the emotion and identity 2-back tasks. Participants were significantly more accurate (A)and faster (B) on the ID task than the EMO task, for all trial types. There was no speed Accuracy tradeoff in performance betweentasks.

RESULTS

fMRI results

EMO>ID task

ID>EMO task

Conjunction

RESULTS

fMRI results

DISCUSSION

significant increase in activity in DLPFC

EMO tasks

ID tasks

Working Memory

increased amygdala activity

increased lateral fusiform gyrus activity

supporting working memory for the faces and expressions of

others.

N-back is a kind of mental training intended to expand your working memory (WM), and hopefully your intelligence (IQ1).

http://www.gwern.net/DNB%20FAQ