Emotional stimuli that are irrelevant to task performance may redirect attentional resources, particularly among individuals evidencing high trait anxiety. EEG markers for this emotional capture of attention and their relation to attention performance

1
Trait Anxiety versus Depression Distinct
Associations with ERP Measures of Emotional
Processing and Attention Tracy Dennis, Chao-Cheng
Chen, Melville Malone, Tara Nolan Michael
ParkerHunter College, City University of New
York

• INTRODUCTION
• Emotional stimuli that are irrelevant to task
  performance may redirect attentional resources,
  particularly among individuals evidencing high
  trait anxiety. EEG markers for this emotional
  capture of attention and their relation to
  attention performance remain unclear. This study
  included a sample of normal adults and examined
  two questions First, whether ERP components
  reflecting initial emotional detection (N1),
  emotional significance processing (early
  posterior negativity (EPN)), and conflict
  monitoring (N2) differed by level of trait
  anxiety and emotional stimulus type second,
  whether these ERP measures of emotional
  processing were related to subsequent attention
  performance.
• Hypotheses
• 1. ERP amplitudes reflecting relatively more
  rapid and automatic emotional detection and
  salience processing (N1, EPN) would be less
  sensitive to trait anxiety compared to more
  top-down executive processing (N2).
• 2. ERP effects would be related to decrements in
  subsequent attentional performance, but this may
  depend on attention system alerting, orienting,
  and conflict resolution.
• 3. We explored these processes in a sub-group of
  the sample showing only high depression, and
  expected unique effects Relatively high levels
  of depression would be associated with reduced
  ERPs overall, particularly to sad faces, due to
  withdrawal of task engagement associated with
  depressed mood.
• METHOD
• Participants. Non-clinical sample including 18
  adults, aged 19-34.
• Trait Anxiety and Depression were measured via
  self-report using the STAI and the BDI.
• The Attention Network Task (Fan et al., 2002).
  This 30-minute task is a combination of a cued
  reaction time and a flanker task that requires
  the subject to determine whether a central arrow
  points to the left or right.
• Emotional Faces were 48 black-and-white
  photographs of fearful, sad, and neutral faces
  (Tottenham et al., 2002).

• RESULTS
• Examination of Trait Anxiety
• Table 1
• Repeated Measures ANOVA at Target Electrode Sites
  (FCz, Cz, PCz, Pz, POz) for Effects of Trait
  Anxiety and Face Type on Peak Amplitudes in Three
  Time Windows (N1, EPN, N2)
• Time window
• Variable df N1 (partial eta²) EPN (partial
  eta²) N2 (partial eta²)
• ELEC 3, 14 6.51 (.58) 10.02 (.68) 7.01
  (.60)
• HEM ANX 1, 16 5.44 (.25)
• EM ELEC ANX¹ 3, 14 3.45 (.43)
• EM ELEC HEM² 3, 14 6.55 (.58)
• p lt .05. p lt .01. p lt .001. ¹ indicates the
  analysis comparing fear and neutral-f trials. ²
  indicates the analysis comparing fear and sad
  trials.

• Preliminary Examination of Depression Groups
• Figure 4. Grand-averaged ERPs at FCz for high
  (solid line) versus low (dashed line) depression
  groups. The N2 was most pronounced in anterior
  electrodes among low versus high depression
  participants across all conditions, but this only
  reached significance following sad faces. These
  N2 amplitudes were negatively correlated with
  orienting (r -0.36).
• FCz High Depression
  Low Depression
• 4 µv
• -4 µv
• DISCUSSION
• Summary of Findings
• For all participants, an N1 component emerged
  around 200 msec in anterior electrodes.
• Later, around 250 msec, an EPN was evident, which
  was greater following fearful but not sad faces.
• In the high versus low trait anxiety group, N2
  amplitudes around 320 msec were greater during
  blocks of trials with fearful faces.
• As N1, EPN, and N2 to fearful faces increased,
  orienting and executive attention decreased, but
  mainly in the high trait anxiety group.
• High depression linked to reduced N2 amplitudes,
  particularly following sad faces, suggesting
  withdrawal from negative emotional stimuli.

Figure 1. The EPN was most pronounced in
posterior versus anterior electrodes,
particularly in the right hemisphere following
fearful faces. High (solid line) versus low
(dashed line) trait anxiety participants
Left Hemisphere Right
Hemisphere Posterior P7 Fear
Sad P8 Fear
Sad 4 µv -4 µv
Anterior C3 C4 4 µv -4
µv Figure 2. The N2 was most pronounced in
anterior electrodes (FCz) among high versus low
trait anxiety participants following fearful and
neutral-f faces. Though the same trend is
apparent in waveforms for sad and neutral-s
faces, statistical tests did not reach
significance. Fear and
Neutral-fear Fear (high low
anxiety) 4 µv -4 µv Sad and
Neutral-sad Sad (high low
anxiety) 4 µv -4 µv Figure 3. As N2 and EPN
amplitudes increased, high but not low trait
anxiety participants showed (a) decreasing
orienting efficiency and (b) greater conflict
interference, respectively. (a) r .39
for high and -.64 for low trait anxiety.
(b) r -.66 for high and -.38 for low trait
anxiety.