There are a number of studies that have explored the relationship between PPI scores and physiological responsiveness during tasks that have an emotional component. Gordon, Baird & End (2004) used Magnetic Resonance Imaging (MRI) whilst their participants took part in two tasks. Participants were shown eight adult faces displaying different emotions; anger, fear, sadness and joy. In the ‘emotional’ task, participants were shown a target face and asked to hit a button when another face was shown displaying the same emotion as the target face. In this task, participants were told not to focus on the gender or identity of the faces shown, only the emotion. In the ‘identity’ task, participants were shown a target face and asked to hit a button when the same face was shown.
assigned to either high PPI or low PPI groups depending on their total PPI score. Gordon et al. (2004) found that there were no differences between the high and low groups in terms of their speed and accuracy on both tasks, which they believe is an encouraging result as there were no differences in performance. However, differences in MRI activity were found between the high and low PPI groups during their performance on the emotional task. The MRI results suggest that there was more activity in the dorsolateral prefrontal cortex for participants with high PPI scores during the emotional task.
Gordon et al. (2004) suggest that activation o f this area o f the brain is associated with working memory and they believe that this is evidence o f use of a cognitive strategy to solve an emotional task. In contrast, the low PPI group showed activity in the inferior frontal, medial prefrontal and amygdala which are the parts o f the brain believed to be responsible for processing information of an emotional nature. It is also of note that the groups did not differ significantly in terms o f the areas o f the brain that were activated during the ‘identity’ task.
Benning et al. (2005) explored the relationship between emotional processing and the subscales of the PPI. Participants’ blink startle responses and electrodermal activity were measured whilst viewing pictures with or without emotional content. The typical
response in healthy individuals is that the magnitude o f the blink startle response is larger during the presentation of negative pictures relative to positive (see chapter 1). Healthy individuals also demonstrate increased electrodermal activity in response to aversive stimuli. Benning et al. (2005) examined the Fearless Dominance (PPI-I) and Self-Centred Impulsivity (PPI-II) scales of the PPI. Participants were each shown pictures from the
International Affective Picture System (IAPS). Benning et al. (2005) only analysed the results of participants with scores in the top and bottom 10% on PPI-I and PPI-II, in order to create extreme groups. A significant difference in startle responses to negative pictures was found between the high and low PPI-I groups. The high PPI-I group demonstrated a reduced blink startle to the negative pictures in comparison to the low PPI-I group. The high PPI-I group had a significantly lower level o f electrodermal activity to negative pictures compared with the low PPI-I group. The low PPI-I group demonstrated an increase in electrodermal activity when viewing negative pictures compared with neutral but the high PPI-I group did not. Participants in the high PPI-I group had significantly lower levels of overall electrodermal activity than the low PPI-I group.
Justus & Finn (2007) also found that in a sample of healthy individuals, males with a high score on the PPI failed to demonstrate the typical increase in startle response when viewing negative material.
These findings are of interest as a number of studies that have found that a high score on the PCL-R is also associated with a reduced blink startle response to negative stimuli (Herpertz & Henning Sass, 2000; Levenston, Patrick, Bradley & Lang, 2000; Patrick, Bradley & Lang, 1993; Vanman, Mejia, Dawson, Schell & Raine, 2003). Vanman et al. (2003) also found that Factor 1 o f the PCL-R is related to reduced blink startle when viewing negative pictures. Participants in this study were also healthy individuals rather than offenders. Patrick, Cuthbert & Lang (1994) also found that a high score on the PCL- R is associated with reduced electrodermal activity when participants were read fearful
sentences compared with neutral sentences. A high score on PPI-I of the PPI-R and Factor 1 of the PCL-R are both associated with reduced blink startle and electrodermal activity when viewing negative slides, which is a significant finding.
Verschuere, Crombez, De Clercq & Koster (2005) examined the relationship between PPI scores and electrodermal activity during a task called the concealed information test, in a sample of 40 male prisoners. During the concealed information test, participants are asked to provide the names of individuals who are important to them and then informed that they were taking part in a lie detection test during which they were required to
attempt to conceal this information. Healthy individuals typically demonstrate an increase in electrodermal activity during this task because they are required to behave in a
deceptive manner. Verschuere et al. (2005) only found a significant negative correlation between PPI-II and electrodermal response (r = -.34). Verschuere et al. (2005) concluded that reduced electrodermal activity during the concealed information test is related to PPI-II.
The results of Benning et al. (2005) and Verschuere et al. (2005) suggest that there is no clear relationship between the underlying factors o f the PPI and physiological
responsiveness during tasks with emotional components. Benning et al. (2005) found that a high score on PPI-I was related to reduced electrodermal activity when viewing
negative slides. However, Verschuere et al.’s (2005) results are unexpected as they found that PPI-II o f the PPI was related to reduced electrodermal activity during the concealed information task. The two tasks are clearly different as the concealed information task did
not actually require participants to respond to emotional material. However, the concealed information task required participants to act in a deliberately deceptive manner, which should also be related to PPI-I rather than PPI-II.
Del Gaizo & Falkenbach (2008) explored the relationship between the PPI and the ability to label emotions in facial expressions (The Diagnostic Analysis of Nonverbal Accuracy - Form 2, DANVA-2-AF; Nowicki & Carton, 1993) and the ability to detect emotion in spoken language (DANVA-2-AP; Nowicki & Carton, 1993). The DANVA-2-AF is a computerised task. Participants are presented with slides of facial expressions depicting happiness, sadness, fear and anger at two different levels of intensity. Low intensity is harder to identify and high intensity is easier. The DANVA-2-AP is a range of sentences, for example, “7 am going out o f the room and I ’ll be back later” spoken in a happy, sad, angry or fearful manner at two different levels of intensity, hard and easy. Participants, who were 175 undergraduate students, were also asked to complete the Positive Affect Negative Affect Scales (PANAS; Watson, Clark & Tellegen, 1988). The PANAS is a self-report tool designed to measure participants’ experience of both positive affect (PA) and negative affect (NA). Participants are presented with 10 PA words (active, alert, attentive, determined, enthusiastic, excited, inspired, interested, proud and strong) and 10 NA words (afraid, ashamed, distressed, guilty, hostile, irritable, jittery, nervous, scared and upset). Participants are asked to report how often they generally experienced each of the 10 PA and NA emotional words.
total score (r = -.18) and PPI-I (Fearless Dominance) (r = -.15) and the recognition of fear measured by the DANVA-2-AF task. No relationship was found between PPI total score, PPI-I or PPI-II and the total number of errors in facial recognition. No relationship was found between the PPI and the DANVA-2-AF which measures emotion conveyed in spoken language.
The two underlying factors of the PPI demonstrated different patterns of results with PA (positive affect) and NA (negative affect). Significant positive correlations of small to moderate effect size were found between PPI-I and all 10 PA emotional words.
Significant positive correlations were also found between PPI total score and two of the PA emotional words, active (r = . 15) and strong (r = . 18). PPI-II demonstrated a negative relationship with PA emotional words but only two of the correlations reached statistical significance, attentive (r = -.16) and interested (r = -.19).
In contrast PPI-I demonstrated a negative relationship with NA emotional words (six reached statistical significance). PPI-II demonstrated a pattern of significant positive correlations of weak to moderate effect size with eight out of the ten NA emotional words. Only correlations with the words nervous and distressed failed to reach statistical significance.
These results suggest that PPI total score and PPI-I are both associated with poorer recognition of fear in facial expressions. PPI-I and PPI-II demonstrated different
with PA whereas PPI-II demonstrated a negative pattern. PPI-I demonstrated an overall negative relationship with NA emotional words and PPI-II demonstrated a positive.