Table of Contents
Remedios et al., 2014
#Paper , CLA salience, CLA Change Detection
A role of the claustrum in auditory scene analysis by reflecting sensory change
[!abstract]+ The biological function of the claustrum remains speculative, despite many years of research. On the basis of its widespread connections it is often hypothesized that the claustrum may have an integrative function mainly reflecting objects rather than the details of sensory stimuli. Given the absence of a clear demonstration of any sensory integration in claustral neurons, however, we propose an alternative, data-driven, hypothesis: namely that the claustrum detects the occurrence of novel or salient sensory events. The detection of new events is critical for behavior and survival, as suddenly appearing objects may require rapid and coordinated reactions. Sounds are of particular relevance in this regard, and our conclusions are based on the analysis of neurons in the auditory zone of the primate claustrum. Specifically, we studied the responses to natural sounds, their preference to various sound categories, and to changes in the auditory scene. In a test for sound-category preference claustral neurons responded to but displayed a clear lack of selectivity between monkey vocalizations, other animal vocalizations or environmental sounds (Esnd). Claustral neurons were however able to detect target sounds embedded in a noisy background and their responses scaled with target signal to noise ratio (SNR). The single trial responses of individual neurons suggest that these neurons detected and reflected the occurrence of a change in the auditory scene. Given its widespread connectivity with sensory, motor and limbic structures the claustrum could play the essential role of identifying the occurrence of important sensory changes and notifying other brain areas—hence contributing to sensory awareness.
Annotations
(20/01/2024, 15:36:02 )
CLA Change Detection: “the claustrum detects the occurrence of novel or salient sensory events” (Remedios et al., 2014, p. 1)
Results are consistent with CLA visual
“It is important to note that we studied claustral neurons only in the context of acoustic stimuli and our findings hence do not speak about the many other claustral neurons that are sensitive to other modalities (Olson and Graybiel, 1980; Remedios et al., 2010). However, our conclusion is well consistent with findings in the visual zone.” (Remedios et al., 2014, p. 6)
[[CLA auditory]]
“Specifically, we studied the responses to natural sounds, their preference to various sound categories, and to changes in the auditory scene. In a test for sound-category preference claustral neurons responded to but displayed a clear lack of selectivity between monkey vocalizations, other animal vocalizations or environmental sounds (Esnd)” (Remedios et al., 2014, p. 1)
“Claustral neurons were however able to detect target sounds embedded in a noisy background and their responses scaled with target signal to noise ratio (SNR)” (Remedios et al., 2014, p. 1)
“The claustrum’s auditory zone may be one such hub in a saliency network. Given claustral projections to structures involved in cognitive and motor control (Pearson et al., 1982; Clascá et al., 1992; Smith and Alloway, 2010; Smith et al., 2012) the claustrum could trigger appropriate behavioral reactions” (Remedios et al., 2014, p. 6)
CLA connections “reciprocally and topographically connects cortical areas and subcortical structures including both early sensory and higher association regions”
“proposed a function based on the claustrum’s most pronounced feature: its widespread anatomical connections throughout the brain. The claustrum reciprocally and topographically connects cortical areas and subcortical structures including both early sensory and higher association regions” (Remedios et al., 2014, p. 1) Gut geschrieben
CLA Change Detection also for properties of visual neurons
“Based on data obtained in a previous study we have suggested that the claustrum may serve as a detector for the occurrence of novel or salient sensory events—saliency here referring to an acoustic difference between a specific sound token and the background auditory scene (Remedios et al., 2010). This hypothesis is not only consistent with our observation of relatively transient responses to auditory stimuli in the primate claustrum (Remedios et al., 2010) but also fits well with reported properties of visual neurons in the claustrum.” (Remedios et al., 2014, p. 2)
CLA periphery connected to CLA salience
“Early pioneering studies on the visual claustrum in the cat found an overrepresentation of the peripheral visual field, that claustral neurons are broadly tuned and respond best to large and moving, hence salient, visual stimuli (Olson and Graybiel, 1980; Sherk and Levay, 1981a).” (Remedios et al., 2014, p. 2) Arousal maybe moving?
“Significant responses were determined using a threshold of three standard deviations of the variability of baseline activity. Only those units were included for group analysis that responded significantly to at least one acoustic condition” (Remedios et al., 2014, p. 3)
[[CLA Change Detection]]
“we found that responses within the same claustral zone could serve well to detect the onset of sounds from silence or the onset of novel sounds within an acoustic background. These results are consistent with previous speculations about a role of the claustrum in novelty or saliency (i.e., critically different from the existing background) (Remedios et al., 2010)” (Remedios et al., 2014, p. 6)
“we found that their response properties point to a role in encoding sound occurrence more than sound category or acoustic qualities” (Remedios et al., 2014, p. 6)
“Our results are well compatible with the claustrum participating in a general novelty or vigilance network” (Remedios et al., 2014, p. 6)
CLA visual: cats’ claustrum for orientation & large Receptive fields
“Sherk and LeVay recorded neurons in the visual claustrum of the cat and found that these neurons were broadly tuned for orientation, with a trend to large receptive fields” (Remedios et al., 2014, p. 6)
“concerning the visual periphery, but generally being sensitive to visual motion (LeVay and Sherk, 1981; Sherk and Levay, 1981a,b)” (Remedios et al., 2014, p. 6)
CLA visual / CLA salience
“Work on the neural underpinnings of visual saliency reported enhanced responses to salient stimuli in those regions potentially implementing the respective saliency map (Constantinidis and Steinmetz, 2005; Arcizet et al., 2011). Interestingly, the neural responses in these areas also scale with the intensity of visual stimuli across a wide range of intensities and exhibit systematically shorter latencies for more salient stimuli (Tanaka et al., 2013)” (Remedios et al., 2014, p. 7)
CLA Change Detection & CLA salience links to individuals with Autism Spectrum Disorder (ASD)
“Additional evidence for a role of the claustrum as novelty detector may be provided by a relation between attentional deficits in Autism spectrum disorders (ASD) and changes in claustral volume in affected individuals. Based on structural imaging it was reported that individuals affected by ASD have a smaller claustral volume compared to control subjects (WB, 2008). The behavioral deficits seen in ASD in turn have been linked to changes in attentional deployment (Klin et al., 2003; Ames and Fletcher-Watson, 2010) and one theory holds that a saliency network prominently involving the insula and possibly neighboring structures is critically involved in ASD (Uddin and Menon, 2009). While not providing direct support for our hypothesis, results such as these are well consistent with the notion of a role of the claustrum in sensory detection.” (Remedios et al., 2014, p. 6)
[[CLA memory]]
“It may well be that the claustrum plays a central role in the formation of memories that facilitate future reactions based on a joint interaction between the claustrum, neuromodulatory systems and the cortex. Further progress towards an improved understanding of the contribution of the claustrum to brain function and cognition hence may benefit from advanced technologies to specifically manipulate activity within this structure or to selectively activate connections between the claustrum and other brain structures (Deisseroth, 2011).” (Remedios et al., 2014, p. 6)
CLA salience: “We therefore believe that our findings are well consistent with a role of the claustrum in a more specialized saliency network.”
(Remedios et al., 2014, p. 7)
“When interpreting the present data it is important to note that the concepts of stimulus novelty or saliency are often used in a loose manner.” (Remedios et al., 2014, p. 7)