Retos en la implementación de acuerdos de solución amistosa:

As described in Chapter Two, typically, faces appear to be a special class of stimuli. Only a few hours after birth, typically developing neonates demonstrate a preference for looking at faces over other stimuli (Goren, Sarty & Wu, 1975; Johnson & Morton, 1991). Results yielded from neuropsychological studies (Calder & Young, 2005; De Renzi et al., 1994) suggest that this pervasive bias to orient visual attention to faces leads to greater experience with faces and in turn enables the development of a cortical network specialised solely for face perception. This highly specialised neural network enables humans to perceive, process and categorise highly complex face stimuli quickly and effectively in order to navigate their social world (Leppanen & Nelson, 2009; Sasson, 2006; Schultz, 2005). If however, this bias to attend to faces is disturbed, resulting in reduced face appraisal experience, then it follows that the development of this specialised neural circuitry would be impaired and would lead to impoverished face

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processing abilities. Some researchers argue that this is the case in ASC (Weigelt et al., 2012). A lack of interest in faces in ASC was first noted in early descriptions by both Kanner (1943) and Asperger (1991). Subsequent studies have demonstrated that people with ASC have a tendency to fixate, not on the human face but instead on socially irrelevant details (Klin et al., 2002; Sasson & Touchstone, 2014; Swettenham et al., 1998). This atypical gaze behaviour, apparent from the very first months of life (Swettenham et al., 1998) has been argued by social attention and motivation theorists (Chevallier et al., 2012) to be the result of abnormal social preferences, and, due to the resultant reduction in face appraisal opportunities may impede typical development and play a role in the socio-emotional processing impairments characteristic of ASC (Riby, Doherty-Sneddon & Bruce, 2008).

For example, Swettenham et al. (1998) found that twenty month old ASC infants looked less at faces and more at objects than non-ASC infants, suggestive of early onset social attention abnormalities in ASC. Swettenham et al.’s (1998) findings offer a potential explanation for

disrupted social learning developmental trajectories and subsequent impoverished face processing abilities in ASC. Klin et al. (2002) observed a similar pattern of non-social attentional preferences in ASC adolescents and adults, suggesting that ASC atypical attentional bias continues into adulthood. Whilst viewing dynamic video clips of social scenes, Klin et al. (2002) found that ASC individuals fixated twice as long on socially irrelevant details and less time orientating attention towards the faces of those in the social scene than did matched non-ASC controls who demonstrated normative social orientation.

However, some studies using static stimuli as opposed to dynamic video clips have failed to find differential eye gaze behaviour in ASC. van der Geest et al. (2002a) presented children with photographs of human faces expressing emotional expressions and found that the gaze fixation patterns of ASC children did not differ from those exhibited by non-ASC controls matched on chronological age, verbal mental age and no-verbal mental age. All participants fixated more on the eye region than other face regions or on non-facial stimuli.

The contradictory findings offered by Klin et al. (2002) using dynamic stimuli and van der Geest

et al. (2002a) using static stimuli led to questions being raised as to the effect of stimulus type or nature on gaze behaviour in ASC. Speer et al. (2007) conducted a study in order to directly address whether face processing deficits in ASC were due to the type of stimuli used in

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empirical studies. Adopting an eye tracking paradigm, Speer et al. (2007) compared the gaze behaviour of HF ASC children and non-ASC matched controls across a number of conditions; social dynamic (video clips of characters interacting), social static (photographs taken from the video clips showing characters interacting), isolated dynamic (video clips of a character shown talking to him/herself or to another character not in shot) and isolated static (photographs taken from the isolated dynamic video clips). Findings supported Klin et al. (2002); when faced with dynamic video footage of characters interacting with one another, ASC participants in spent significantly less time compared to controls looking at the eyes of the characters and spent more time relative to controls looking at the character’s body. Comparisons of gaze behaviour in all other conditions however did not differ between groups and therefore also confirmed van der Geest et al.’s (2002a) findings of normative gaze behaviour for isolated static social stimuli. It

appears that gaze behaviour in ASC only becomes atypical if the social scene being viewed is both realistic and social in nature. This finding fits nicely with the empathy imbalance hypothesis of ASC (Smith, 2009). ASC individuals may not spontaneously attend to particularly salient features of their social environment in order to limit their empathic arousal and the subsequent discomfort this causes.

To summarise, research suggests that indeed, there is a face-specific recognition impairment in ASC, with deficits observed in memory for faces (Boucher & Lewis, 1992; Hauck et al., 1998; McPartland et al. 2011; Snow et al., 2011). Furthermore, atypical neural functioning in response to viewing faces has been observed in ASC (Hubl et al., 2003; Piggot et al., 2004). Empirical evidence suggests an attentional bias in ASC for non-social information over social information (such as faces) especially when the social stimuli is dynamic and more naturally occurring. Collectively, these findings suggest that disturbed face-specific neural circuitry development in ASC may result in part, from reduced experience with facial stimuli as a result of atypical attentional bias.