Personality, associative learning and related cortical activity

Abstract The objective of this study was to identify cortical activity (theta and alpha rhythms) connected to learning and two neural systems behind personality related behaviour; behavioural inhibition system (BIS) and behavioural activation system (BAS). Electro-encephalography (EEG) was recorded while human participants were subjected to eyeblink conditioning procedure. Delay and trace eyeblink conditioning paradigms were employed in parallel: in the delay paradigm a 850 ms tone as conditioned stimulus (CS) and a 100 ms air puff as unconditioned stimulus (US) and in the trace paradigm a 250 ms tone as conditioned stimulus and a 100 ms airpuff as unconditioned stimulus separated by a 500 ms trace period. A silent movie was used as a masking task during the experiment. Recordings from twenty-one electrodes were analysed and subjects divided into personality groups based on the results from personality questionnaire and into learning groups based on the amount of conditioned responses. We found that subjects with a low score in BIS-scale learned better than subjects higher on the scale. The low-BIS group also showed more theta activity and less lower-alpha activity during the experiment. The group of good learners had higher level of theta activity and less lower-alpha activity than the group of poor learners during the experiment. These findings verify the connection between learning rate and theta activity. According to our results of personality related brain activity, it can be seen that BIS and BAS are distinct brain structures that are differently reflected on both learning rate and theta activity. Contradictory findings with previous studies validate the need for further research about EEG-correlates of personality.