Orientación y objetivos del documento

Individuals who engage in antisocial behaviour are supposed to have chronically low

levels of physiological arousal (Raine, 1996; van Goozen et al., 2007). Evidence for

this comes from numerous measures of autonomic and central nervous system

functioning including skin conductance activity (Fowles, 1993; Raine, Venables, &

Williams, 1990a), heart rate (Ortiz & Raine, 2004), resting EEG (Raine, Venables, &

Williams, 1990b), and hypothalamic-pituitary-adrenal axis (HPA) activity

(McBurnett et al., 1991; van Goozen et al., 1998) . There are three differing

16 seeking theory (Zuckerman, 1979), the low fear hypothesis (Raine, 2002), and the

somatic marker hypothesis (Bechara & Damasio, 2005).

1.1.7.1. Sensation seeking.

The sensation seeking theory (Zuckerman, 1979) proposes that there is an optimal

level of arousal which an individual can experience and being below this optimal

level is an aversive state in which individuals are motivated to eliminate. As a result,

those with tonically low levels seek out stimulation to raise their arousal levels. One

such source of stimulation is antisocial behaviour. Support for this theory comes

from El-Sheikh, Ballard, and Cummings (1994), who found that preschool boys who

choose to watch videos of people showing intense anger, had lower resting heart

rates in comparison to those that chose to watch videos of a more mild depiction of

anger. In addition, these boys who were more sensation seeking also demonstrated

increased levels of externalising behaviour. Furthermore, longitudinal data also

support this theory. Raine, Venables, & Mednick (1997) found that the resting heart

rate of children at age 3 years predicted sensation seeking and aggression when they

were 11 years old. Further, Gower and Crick (2011) found that both lower systolic

and diastolic blood pressure and lower heart rate predicted increased engagement in

classroom physical and relational aggression. A recent systemic review and meta-

analysis of 114 studies (Portnoy & Farrington, 2015) also suggests that the

relationship between low resting heart rate and antisocial behaviour is highly

replicable. Many of the studies in the review explored this relationship in those with

CD, 11 of which found a negative relationship between low resting heart rate and

antisocial behaviour, while 5 found a positive relationship (low resting heart rate was

associated with reduced antisocial behaviour), therefore the finding is not always

17 behaviour, as there are many activities that one can engage in that are stimulating

and yet not antisocial. Therefore, a sensation seeking disposition must interact with

other factors.

1.1.7.2. Low fear hypothesis.

The low fear hypothesis was originally put forward by Lykken (1957, 1995) to

explain the development of psychopathy (although it has also been used to explain

antisocial behaviour in general; Raine, 2002b). Lykken coined the term ‘fear

quotient’ to refer to an individual’s temperamental fearfulness. In his model, fear is described as “an aversive state that elicits arousal and escape behaviour (Lykken, 1995, p. 135). Therefore an individual’s fear quotient represents the extent of arousal that is experienced, and this is variable across individuals. A fear reaction to some

stimuli is innate, such as an unexpected loud noise, while fear of less explicitly

aversive stimuli is learned via the conditioning process. When a behaviour leads to

an aversive outcome, an association is made between the act and the outcome. As a

result, when an individual has an impulse to commit this act, fear will be elicited due

to its previous pairing with the aversive outcome (Lykken, 1995) and therefore will

be likely to avoid the act in the future. If the individual avoids the act they will also

receive negative reinforcement due to the avoidance of the aversive state, which will

increase the likelihood of further avoidance in the future. Psychopaths (who are

characterised by a deficient experience of emotion, an arrogant and deceitful

interpersonal style, and behaviours characterised by impulsivity and irresponsibility,

and importantly elevated level of antisocial behaviour; Cooke & Michie, 2001) are

argued to show a low fear quotient, and therefore a reduced experience of fear. This

low fear quotient means psychopaths will be less likely to avoid the punished act.

18 ineffective which also creates difficulties in the socialisation processes that rely on

learning through punishment (Lykken, 1995) and a lack of socialisation may lead to

poor conscience development (Raine, 1993). Importantly, this deficit is argued to be

specific to fear, rather than an attenuated experience of emotion in general (Lykken,

1995). The low fear theory’s relevance to antisocial behaviour in childhood is supported by research findings that low autonomic nervous system (ANS) and

hypothalamic-pituitary-adrenal (HPA) axis arousal provides the groundwork for a

disinhibited, fearless temperament in infancy and childhood (Baker, Shelton,

Baibazarova, Hay, & van Goozen, 2013; Kagan, Reznick, & Snidman, 1987; Scarpa,

Raine, Venables, & Mednick, 1997). Such low levels of arousal have also been

argued to reflect a more general risk factor for antisocial behaviour because those

with low arousal will have problems being attentive to and responding to

environmental cues that help with decision making and guiding behaviour. Such a

relationship has been conceptualised in the somatic marker hypothesis (Bechara &

Damasio, 2005).

1.1.7.3. The somatic marker hypothesis.

The somatic marker hypothesis (Bechara & Damasio, 2005) is based on the

assumption that there is a cortical-subcortical system (which includes the frontal

lobes and the limbic system) involved in decision making. Such decision making is

influenced to a large extent by affect processes. The “marker” described by the somatic marker hypothesis is an emotional-visceral marker that guides experience

and as a result influences decision making. The production of the somatic marker is

thought to be generated by the ventromedial prefrontal cortex (vmPFC) and/or the

amygdala due to research showing that damage to these areas results in an inability

19 & Harris, 2000). These states are expressed as changes in bodily arousal (e.g.

changes in heart rate, skin conductance).

The prefrontal cortex is argued to be the primary region that integrates all

sensory and affective information into a cognitive amalgam (Damasio, 1996;

Damasio, Tranel, & Damasio, 1990). When people are exposed to situations which

involve elements that have previously been organised and classified affectively,

these past markers are activated to guide subsequent cognition and decision making.

For example, an experience already marked as ‘bad’ produces a somatic state (e.g.

increased heart rate) that acts as a signal in guiding subsequent experience. In the

case of this negative marker the result may be to avoid the situation. Applying this to

antisocial acts, in a healthy individual, when faced with a decision to commit an

antisocial act, there will be activation of the association between the antisocial act

and a previous associated punishment and therefore result in emotional aversion.

Evidence for the somatic marker hypothesis comes from studies that have

explored patients’ with vmPFC and amygdala lesions (areas known to be involved in emotion processing; Sobhani & Bechara, 2011) who performed the IOWA gambling

task (Bechara, Tranel, & Damasio, 2000). This task requires participants to choose

between decks of cards which either result in large immediate rewards and high

future losses (disadvantageous decks) or decks which result in lower immediate gain

but smaller future loss (advantageous decks). The typical finding on this task is that

healthy control participants (without vmPFC or amygdala lesions) have a preference

for the advantageous decks, while participants with the above lesions prefer the

disadvantageous decks (Bechara, Tranel, & Damasio, 2000). Skin conductance

activity was also measured while participants completed this task. Interestingly,

20 to selecting a card, which suggests that they were beginning to react to imagined

scenarios (i.e., they were anticipating the potential contingency before they were

explicitly aware of the result). Participants with vmPFC lesions, on the other hand,

although generating SCRs to the immediate rewards or punishment, did not generate

anticipatory SCRs while choosing a deck. Furthermore, when examining the SCRs

of participants with amygdala lesions, it was found that not only did they fail to

generate anticipatory SCRs, but they also failed to generate them in response to the

rewards or losses (Bechara, Damasio, Damasio, & Lee, 1999). Along with providing

evidence for the somatic marker hypothesis, this study gave some insight into the

different functions of the vmPFC and amygdala. Both groups were impaired in their

ability to make decisions, but the amygdala seems to be crucial in attaching an

affective or emotional label to the stimuli, while the vmPFC seems to be involved in

integrating or attaching the emotional marker to the associated event.

The above theories centre around deficits in arousal in explaining antisocial

behaviours, next theories will be introduced that suggest that impairments in the

processing of the emotions of others lead to antisocial behaviour.

1.1.8. The Processing of the Emotions of Others

In document herreria (página 181-185)