Neuroimaging in cockroach phobia: An experimental study

Abstract

Background/ObjectiveIn this study we explored the neuroimaging characteristics of persons with specific small animal (cockroach) phobia to determine whether there are differences in cerebral activity between persons with and without cockroach phobia under conditions of phobic and non-phobic stimulation. Method: 24 adult persons (12 with phobia) were studied. The diagnosis of phobia was obtained with a structured interview and questionnaires. All participants were exposed to a 3D video presentation during an fMRI session. Results: The phobic group showed significant differential activations that were congruent with a dual route model of fear processing through the thalamus-amygdala (route I) and the thalamus-sensory and association cortex-entorhinal cortex-hippocampus-subiculum-amygdala (route II). Apart from this dual route, we also found differential activations in the globus pallidum, parahippocampal gyrus, insula, pars orbitalis, triangularis and opercularis of the frontal cortex, and cerebellum. Respect to non-phobic group, no activations were found in the insula or the anterior cingulate cortex. Conclusions: There seems to be a dual route depending on how persons with phobia to cockroaches process phobic stimuli. This double processing can have implications for the psychological treatment of specific phobias.

The Equivalence between Virtual and Real Feared Stimuli in a Phobic Adult Sample: A Neuroimaging Study

“…Figure 5 shows activation of the insula. A similar activation was found in the right insula (42,24,2) with both real and virtual images. Yet, in the left insula, real images were associated with greater intensity (Z = 7.10; p < 0.000; Z = 6.22; p < 0.000; Z = 5.47; p < 0.000; Z = 5.45; p < 0.000) and extension (42, 24, 2; −46, 12, −6; −30, −28, 22; 38, −28, 22).…”

“…Compared to the limbic areas, frontal areas have been found to be less consistent and less stable in processing phobic stimuli. These findings are congruent with the existence of a dual-route functional network in processing feared stimuli [21][22][23][24]: Wave1, a short/unconscious route that involves a direct link between the thalamus and the amygdala; and Wave2, a long/conscious route that involves the thalamus-sensory and cortex-entorhinal cortex-hippocampus-subiculum-amygdala.…”

Cockroaches are scarier than snakes and spiders: Validation of an affective standardized set of animal images (ASSAI)

“…Additionally, the current results might be useful for further investigations specifically interested in the study of cockroach phobia. In this line, a recent fMRI study has described the emotional brain circuits involved in cockroach phobia when phobic people watched cockroach images compared to non-phobic people (Rivero et al, 2017 ). Those results are comparable to prior findings reported in neuroimaging studies focused on snake phobia (Schaefer et al, 2014 ), describing a similar strong activation of specific brain areas when phobic people are confronted with the stimulus they fear.…”

“…In this regard, an increasing number of studies are focusing on cockroach phobia treatments with the aim of developing new, more accepted treatments as potential alternatives to applying the exposure technique supported by ICTs, as in virtual reality or augmented reality (e.g., Botella et al, 2005 ; Botella et al, 2008 ; Botella et al, 2010 ). From the neurocognitive research field, there is also recent empirical evidence from an fMRI study focused on the neural processes involved in cockroach phobia (Rivero et al, 2017 ).…”

Neuronal Correlates of Small Animal Phobia in Human Subjects through fMRI: The Role of the Number and Proximity of Stimuli

“…Similarly, the vermis of the cerebellum, which is associated with the planning and initiation of movement (i.e., escape behavior), was affected by proximity of the feared stimulus in participants with phobia. Previous neuroimaging studies have highlighted increased cerebellar changes [ 16 , 35 , 36 ] associated with specific phobia and shown the relevance of the cerebellum as a potential clinical marker of anxiety [ 37 ] related to difficulties in emotion regulation [ 38 ]. The number of feared stimuli was associated with greater activation of different brain areas related mainly to a larger network of the motor system, including the precentral cortex and attentional network.…”