Autism spectrum disorders (ASD) represent a set of neurodevelopmental lifelong disorders characterized by deficits of social interactions, impairments in communication skills, as well as excessively repetitive and stereotyped patterns of behavior, interests, and activities (American Psychiatric Association 2013; World Health Organization 2010).
In particular, subjects with ASD can present temporary behaviors of acute agitation and aggressiveness. In fact, they can display momentary maladaptive and challenging behaviors as oppositional or disturbing activities as well as more severe behaviors such as self-injuries or aggressions. These multiple agitation forms are often called, for short, problem behaviors (or crisis behaviors) (Horner Reference Horner2010; Stark et al. Reference Stark, Barnes, Young and Gabriels2015).
The problem behavior has been defined as the “tip of the iceberg” because it seems to be the result of many different underlying variables interplaying in a complex way (Mesibov et al. Reference Mesibov, Shea and Schopler2004). Interestingly, in a very recent experimental work (Tonello et al. Reference Tonello, Giacobbi, Pettenon, Scuotto, Cocchi, Gabrielli and Cappello2018), ASD problem-behavior dynamics have been shown to fit the self-organized criticality (SOC) model.
The SOC is commonly used to describe natural phenomena and systems such as earthquakes, riverbank failures, and landslides, where a type of “catastrophic event is necessary in order to maintain a “critical equilibrium” (Bak Reference Bak1997). As a SOC toy model, suppose we drop some grains of sand on a small, round table: Grain upon grain, a sand-pile forms in the shape of a cone. It keeps growing until the table surface is completely covered, and over it, a defined cone shape is reached. At this point, adding new grains won't change the pile shape any more. In fact, adding grain after grain will cause, suddenly and occasionally, landslides on the pile surface so that the target shape is maintained. So, the pile organizes itself (as a definite cone) and maintains its critical equilibrium through “catastrophic events” (i.e., landslides).
According to the SOC model, “stressors” for an ASD subject would act as the grains of sand. As grains drop on the pile, so stressors occur in her or his life (Stark et al. Reference Stark, Barnes, Young and Gabriels2015). As they interact (in a complex way) in the sand-pile, so they interplay within a subject. Similarly to a landslide in a sand-pile, they cause a form of crisis behavior in an ASD subject. Namely, problem behavior is a type of symptom resulting from a complex network of interacting stressors.
Notably, scientific literature can identify stressors as internal (e.g., a feeling of hunger), as well as external (e.g., noise from a car's horn) (Mesibov et al. Reference Mesibov, Shea and Schopler2004). Now, it is reasonable to consider such stressors as being related to “intentional information” making sense in Davidson and Dennett interpretivism (Davidson Reference Davidson1984; Dennett Reference Dennett1987), just as suggested by Borsboom et al. in the target article. As described in the network models, a symptom (e.g., a type of communication ability impairment) can interact with stressors (e.g., feeling of hunger) while another symptom (e.g., hyper-reactivity to sounds) can interact with other stressors (e.g., a car's honking horn). This complex interplay of symptoms and stressors could lead to, for example, a challenging behavior, a peculiar symptom within the family of what has been called problem behaviors (in turn, feeding the social impairment, another fundamental ASD feature, thus taking place within the network).
Therefore, in our opinion, the network model proposed by Borsboom et al. seems to be highly consistent with the body of published literature regarding ASD problem behaviors and, particularly, with the recently proposed SOC model.
Interestingly, the SOC model could suggest new possible insights. In fact, according to Borsboom et al., “‘to suffer from a disorder’ means ‘to be trapped in the stable state of a self-sustaining symptom network’” (sect. 3, para. 3). The SOC perspective could additionally suggest the network as a self-organized system, in which symptoms are “necessary” events that maintain a type of critical equilibrium (Ramos Sassi Piqueira Reference Ramos, Sassi and Piqueira2011). For instance, as for ASD, can we think of panic attacks as “landslides” in the “sand-pile” of panic disorders, or of sad moods as landslides in the sand-pile of major depression?
Hence, a pathological state would not be just a “stable state” but a “critical state of equilibrium” of a self-organized complex interaction of stressors and symptoms, just like grains in a sand-pile.
Autism spectrum disorders (ASD) represent a set of neurodevelopmental lifelong disorders characterized by deficits of social interactions, impairments in communication skills, as well as excessively repetitive and stereotyped patterns of behavior, interests, and activities (American Psychiatric Association 2013; World Health Organization 2010).
In particular, subjects with ASD can present temporary behaviors of acute agitation and aggressiveness. In fact, they can display momentary maladaptive and challenging behaviors as oppositional or disturbing activities as well as more severe behaviors such as self-injuries or aggressions. These multiple agitation forms are often called, for short, problem behaviors (or crisis behaviors) (Horner Reference Horner2010; Stark et al. Reference Stark, Barnes, Young and Gabriels2015).
The problem behavior has been defined as the “tip of the iceberg” because it seems to be the result of many different underlying variables interplaying in a complex way (Mesibov et al. Reference Mesibov, Shea and Schopler2004). Interestingly, in a very recent experimental work (Tonello et al. Reference Tonello, Giacobbi, Pettenon, Scuotto, Cocchi, Gabrielli and Cappello2018), ASD problem-behavior dynamics have been shown to fit the self-organized criticality (SOC) model.
The SOC is commonly used to describe natural phenomena and systems such as earthquakes, riverbank failures, and landslides, where a type of “catastrophic event is necessary in order to maintain a “critical equilibrium” (Bak Reference Bak1997). As a SOC toy model, suppose we drop some grains of sand on a small, round table: Grain upon grain, a sand-pile forms in the shape of a cone. It keeps growing until the table surface is completely covered, and over it, a defined cone shape is reached. At this point, adding new grains won't change the pile shape any more. In fact, adding grain after grain will cause, suddenly and occasionally, landslides on the pile surface so that the target shape is maintained. So, the pile organizes itself (as a definite cone) and maintains its critical equilibrium through “catastrophic events” (i.e., landslides).
According to the SOC model, “stressors” for an ASD subject would act as the grains of sand. As grains drop on the pile, so stressors occur in her or his life (Stark et al. Reference Stark, Barnes, Young and Gabriels2015). As they interact (in a complex way) in the sand-pile, so they interplay within a subject. Similarly to a landslide in a sand-pile, they cause a form of crisis behavior in an ASD subject. Namely, problem behavior is a type of symptom resulting from a complex network of interacting stressors.
Notably, scientific literature can identify stressors as internal (e.g., a feeling of hunger), as well as external (e.g., noise from a car's horn) (Mesibov et al. Reference Mesibov, Shea and Schopler2004). Now, it is reasonable to consider such stressors as being related to “intentional information” making sense in Davidson and Dennett interpretivism (Davidson Reference Davidson1984; Dennett Reference Dennett1987), just as suggested by Borsboom et al. in the target article. As described in the network models, a symptom (e.g., a type of communication ability impairment) can interact with stressors (e.g., feeling of hunger) while another symptom (e.g., hyper-reactivity to sounds) can interact with other stressors (e.g., a car's honking horn). This complex interplay of symptoms and stressors could lead to, for example, a challenging behavior, a peculiar symptom within the family of what has been called problem behaviors (in turn, feeding the social impairment, another fundamental ASD feature, thus taking place within the network).
Therefore, in our opinion, the network model proposed by Borsboom et al. seems to be highly consistent with the body of published literature regarding ASD problem behaviors and, particularly, with the recently proposed SOC model.
Interestingly, the SOC model could suggest new possible insights. In fact, according to Borsboom et al., “‘to suffer from a disorder’ means ‘to be trapped in the stable state of a self-sustaining symptom network’” (sect. 3, para. 3). The SOC perspective could additionally suggest the network as a self-organized system, in which symptoms are “necessary” events that maintain a type of critical equilibrium (Ramos Sassi Piqueira Reference Ramos, Sassi and Piqueira2011). For instance, as for ASD, can we think of panic attacks as “landslides” in the “sand-pile” of panic disorders, or of sad moods as landslides in the sand-pile of major depression?
Hence, a pathological state would not be just a “stable state” but a “critical state of equilibrium” of a self-organized complex interaction of stressors and symptoms, just like grains in a sand-pile.