TMS to the Lateral Occipital Cortex Disrupts Object Processing but Facilitates Scene Processing

Abstract

The study of brain-damaged patients and advancements in neuroimaging have lead to the discovery of discrete brain regions that process visual image categories, such as objects and scenes. However, how these visual image categories interact remains unclear. For example, is scene perception simply an extension of object perception, or can global scene "gist" be processed independently of its component objects? Specifically, when recognizing a scene such as an "office," does one need to first recognize its individual objects, such as the desk, chair, lamp, pens, and paper to build up the representation of an "office" scene? Here, we show that temporary interruption of object processing through repetitive TMS to the left lateral occipital cortex (LO), an area known to selectively process objects, impairs object categorization but surprisingly facilitates scene categorization. This result was replicated in a second experiment, which assessed the temporal dynamics of this disruption and facilitation. We further showed that repetitive TMS to left LO significantly disrupted object processing but facilitated scene processing when stimulation was administered during the first 180 msec of the task. This demonstrates that the visual system retains the ability to process scenes during disruption to object processing. Moreover, the facilitation of scene processing indicates disinhibition of areas involved in global scene processing, likely caused by disrupting inhibitory contributions from the LO. These findings indicate separate but interactive pathways for object and scene processing and further reveal a network of inhibitory connections between these visual brain regions.

TMS to the “occipital face area” affects recognition but not categorization of faces

“…This null result is not definitive and should be interpreted cautiously. Previous research has shown that object categorization can be impaired with TMS to area LO using a protocol similar to that in the current study (Mullin and Steeves, 2011). It is possible that face categorization could be impaired by TMS if one could access deeper brain structures in the face network, particularly the FFA.…”

“…TMS was delivered at 10 Hz and 60% of maximal stimulator output, similar to previous studies (e.g. Mullin & Steeves, 2011;Pitcher et al, 2007). The frequency, intensity and duration of the TMS train were well within the TMS safety limits (Wassermann, 1998;Rossi, Hallett, Rossini, & Pascual-Leone, 2009).…”

“…Previous studies have demonstrated that 30 ms is sufficient time to make accurate visual categorization judgments (Thorpe, Fize, & Marlot, 1996;Fabre-Thorpe, 2011). Recent findings have shown that TMS to predefined regions of interest can disrupt categorization at such short display durations (Mullin & Steeves, 2011;Ganaden, Mullin, & Steeves, 2013).…”

The role of the lateral occipital cortex in aesthetic appreciation of representational and abstract paintings: A TMS study

“…Three TMS pulses were delivered at onset of each painting, given prior TMS evidence showing that contribution of LO to object processing takes place within the first 180 ms of stimulus onset (e.g. Mullin & Steeves, 2011), and that triple-pulse 10 Hz TMS has been used before to interfere with underlying cortical activity (e.g., Cohen Kadosh et al, 2007;see Bona, Herbert, Toneatto, Silvanto, & Cattaneo, 2014 for triple-pulse 10 Hz TMS over LO region). Stimulation order was counterbalanced across participants.…”

Evidencing a place for the hippocampus within the core scene processing network

“…As such, it is unsurprising that functional neuroimaging techniques have revealed a putative “core” scene processing network in the human brain that responds strongly when viewing navigationally relevant stimuli (e.g., scenes) versus other visual categories. This core network is thought to include posterior parahippocampal gyrus [PHG; Aguirre et al, 1998a; Epstein et al, 2003; Epstein and Kanwisher, 1998], retrosplenial cortex [RSC; Auger et al, 2012; Epstein et al, 2007; Vann et al, 2009] and the transverse occipital sulcus [TOS; Dilks et al, 2013; Ganaden et al, 2013; He et al, 2013; Mullin and Steeves, 2011; Nasr et al, 2011]. As seen in the neural processing of other visual categories [Taylor and Downing, 2011], these regions appear to support distinct but complementary aspects of scene processing, and are differentially modulated by changes in viewpoint [Epstein et al, 2003, 2007; Park and Chun, 2009], spatial layout [Harel et al, 2013; Park et al, 2015], and lower‐level spatial features [Kravitz et al, 2011a; Nasr et al, 2014].…”