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Limbic abnormalities in affective processing by criminal psychopaths as revealed by functional magnetic resonance imaging. By: Kent A Kiehl, Andra M Smith,

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Presentation on theme: "Limbic abnormalities in affective processing by criminal psychopaths as revealed by functional magnetic resonance imaging. By: Kent A Kiehl, Andra M Smith,"— Presentation transcript:

1 Limbic abnormalities in affective processing by criminal psychopaths as revealed by functional magnetic resonance imaging. By: Kent A Kiehl, Andra M Smith, Robert D Hare, Adrianna Mendrek, Bruce B Forster, Johann Brink, Peter F Liddle. Presented by: Richard Rigby

2 -Psychopaths are characterized by a deficit in processing affective material* which can lead to symptoms such as: -superficiality -lack of empathy, guilt, or remorse -failure to experience or appreciate the significance of emotional stimulus *Affective material: something that elicits an emotional response. Who are Psychopaths?

3 -1% of the general population are psychopaths % of the prison population are psychopaths -Using SPECT it was found that psychopaths show greater bilateral activation for affective stimuli in the temporofrontal cortex. -This suggests psychopaths require more activation in areas outside the limbic system to evaluate effective stimuli -Many other structures have been suggested to cause psychopathy, yet little was known about their involvement Previous Research

4 Using an fMRI (1.5 T) to measure emotional processes in the brain activated by an affective memory task. Purpose

5 Participants: -Criminals from a maximum security prison in Abbotsford BC -Criminal psychopaths (n=8) -Criminal non-psychopaths (n=8) -Healthy participants from general population (n=8) -All participants were controlled to have no significant difference in: -Years of substance abuse -Age -Parental socioeconomic status -IQ -The Hare Psychopathy Checklist-Revised assessed psychopathy Participants

6 -Affective (lack of empathy) -Interpersonal (manipulative) -Antisocial (keep going back to jail) -Lifestyle (craves high stimulation, unreasonable goals) PCL-R 4 Dimensions:

7 Procedure - Encoding: subjects memorized 12 words shown on a screen one at a time (0.5s to view word, 1.5 in between) chaircarfishtoaster

8 Procedure - Rehearsal: participants were told to rehearse words rehearse

9 Procedure - Recognition: 12 words presented, participants were asked if the word was present in the first sequence (2s to view word, 0.5s in between). chaircatboxtoaster

10 Procedure -Repeated 8 times -On half the trials all words were neutral (Ex. Chair) -The other half were negative words (Ex. Hate) which were used as an affective stimuli hatekillpunchcry

11 Results -Psychopaths showed less activation than non- psychopaths in response to the affective stimuli in: -rostral and cuadal anterior cingulate -posterior colingulate -left inferior frontal gyrus -right and left amygdala -ventral striatum -parahippocampal gyrus -bilateral anterior superior temporal gyrus

12 Results -Psychopaths showed less activation than non- psychopaths in response to the affective stimuli in: -All are areas of the Limbic System or Frontal Lobe

13 Results -Psychopaths showed greater activation outside the limbic system in response to affective stimuli: -left anterior superior temporal gyrus -left anterior inferior frontal gyrus -right inferior frontal gyrus

14 Discussion -Psycopathy is a result of limbic system and frontal lobe abnormalities, which affect: -The ability to process emotions (amygdala, ventral striatum, and hippocampal formation) -Memories (amygdala, ventral striatum, and hippocampal formation) -Fear of punishment (amygdala) -Psychopaths use non-limbic regions more than non-psychopaths to process affective stimuli.

15 Discussion -Limitations:-Small sample size -Substance abuse could have altered results Future experiments:-Different affected stimuli (faces)

16 My Opinion Pros -Lots of previous research -They controlled confounds very well in their participants -They included brain images -Thorough explanation of results Cons -The images weren’t great -Lots of complicated jargon about random effects analysis -Complicated large tables

17 References Kiehl, K. A., et al (2001). Limbic abnormalities in affective processing by criminal psychopaths as revealed by functional magnetic resonance imaging. Bio Psychiatry, 50, Recommende d by Psych prof


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