Attention Reshapes Receptive Fields for Thermal and Tactile Perception
Poster No:
2482
Submission Type:
Abstract Submission
Authors:
Dongho Kim1, Sohyun Han2, Seongyun Kim1, Seulgi Eun1, Choong-Wan Woo3, Min-Suk Kang4, Seong-Gi Kim5
Institutions:
1Center for Neuroscience Imaging Research, IBS, Suwon-Si, Gyeonggi, 2Res. Equipment Operations Div., Korea Basic Sci. Inst., Cheongju, Chungbuk, 3Center for Neuroscience Imaging Research, IBS, Suwon-si, Gyeonggi-do, 4Sungkyunkwan University, Seoul, Seoul, 5Center for Neuroscience Imaging Research (CNIR), Institute for Basic Science (IBS), Suwon, Korea, Republic of
First Author:
Co-Author(s):
Seong-Gi Kim
Center for Neuroscience Imaging Research (CNIR), Institute for Basic Science (IBS)
Suwon, Korea, Republic of
Center for Neuroscience Imaging Research (CNIR), Institute for Basic Science (IBS)
Suwon, Korea, Republic of
Introduction:
Imagine a scenario where the wrist is subjected to high-temperature thermal stimulation, causing pain, while simultaneously, the finger receives a light vibrational stimulus. Intriguingly, shifting attention from the wrist to the finger has been found to temporarily reduce wrist pain(Kim, Woo et al. 2022). However, understanding the mechanisms of this pain reduction in the primary somatosensory cortex (S1) remains a challenge. The S1 cortex, comprising six neuronal layers with distinct neuron types and connections, plays a crucial role in sensory processing(Liang, Mouraux et al. 2013). Thalamic inputs predominantly synapse with neurons in the middle layer of S1. In contrast, feedback from higher-order brain areas typically targets both the deep and superficial layers(Yu, Huber et al. 2019). Additionally, feedforward lateral connections through the superficial layers of S1 are also important in the cortex's sensory processing functions(Douglas and Martin 2004). If attention diversion to the finger alleviates pain through cortico-cortical feedforward lateral inputs in the superficial layer near the wrist, we would expect an increase in BOLD (blood oxygen level-dependent) signals in the superficial layers of S1 associated with the wrist.
Methods:
In the fMRI study, participants engaged in a tactile discrimination task focusing on finger stimuli, accompanied by an unattended tactile or heat stimulus (44 degrees Celsius) on the wrist. The fMRI protocol included 18-second stimulations on fingers and wrist, alternating with 36-second rest periods, over eight cycles per run, totaling eight runs. This setup was designed to monitor the BOLD signal within the S1 cortex, with a focus on signal sensitivity at 0.8 mm isotropic resolution and 35 slices, and a repetition time (TR) of 3 seconds for accurate BOLD contrast mapping(Han, Eun et al. 2021, Han, Eun et al. 2022). The behavioral experiments involved applying tactile stimuli to one of eight distinct forearm areas per trial, with participants identifying the stimuli locations. Additionally, in a dual-task condition, participants performed a frequency discrimination task on the fingers while locating stimuli on the forearm.
Results:
The fMRI study revealed a significant reduction in BOLD signals across the middle, superficial, and deep layers of the S1 cortex in the wrist region when attention shifted to the finger. This reduction was notable not just in the layer receiving thalamic input but also in layers associated with feedback. These findings suggest that pain reduction mechanisms are more likely linked to diminished bottom-up input, modulated in the thalamus through attentional mechanisms, rather than to cortico-cortical feedforward inputs. Additionally, the S1 receptive field for the wrist's thermal stimulation showed a lateral shift. This shift led to a notable change in the BOLD signal, most pronounced in the middle layer. This pattern indicates that the receptive field shift is likely due to direct feedforward input from the thalamus, not cortico-cortical lateral feedforward input via the superficial layer, providing strong evidence of attention's role in shifting the receptive field within the human sensory cortex.
In the behavioral experiments, participants showed higher accuracy in identifying stimuli at the forearm array's extremities compared to the middle, leading to the concept of 'endpoint bias'. This finding suggests increased sensitivity or responsiveness at the array's endpoints. During the dual-task condition, a perceptual shift was observed from the extremities to the middle of the forearm, indicating a reconfiguration of the receptive field for forearm stimulation when attention is focused on finger tasks.
In the behavioral experiments, participants showed higher accuracy in identifying stimuli at the forearm array's extremities compared to the middle, leading to the concept of 'endpoint bias'. This finding suggests increased sensitivity or responsiveness at the array's endpoints. During the dual-task condition, a perceptual shift was observed from the extremities to the middle of the forearm, indicating a reconfiguration of the receptive field for forearm stimulation when attention is focused on finger tasks.
Conclusions:
The integration of fMRI and behavioral studies reveals how the receptive field for painful stimulation is dynamically reconfigured by diverting attention from the painful area. This reconfiguration is underpinned by mechanisms originating in the thalamus.
Perception, Attention and Motor Behavior:
Attention: Auditory/Tactile/Motor
Perception: Pain and Visceral
Perception: Tactile/Somatosensory 2
Perception and Attention Other 1
Keywords:
Cognition
Cortical Layers
FUNCTIONAL MRI
Pain
Perception
1|2Indicates the priority used for review
Provide references using author date format
Han, S. (2021). "Improvement of sensitivity and specificity for laminar BOLD fMRI with double spin-echo EPI in humans at 7 T." Neuroimage 241: 118435.
Han, S. (2022). "Improved laminar specificity and sensitivity by combining SE and GE BOLD signals." Neuroimage 264: 119675.
Kim, D. (2022). "Neural mechanisms of pain relief through paying attention to painful stimuli." Pain 163(6): 1130-1138.
Liang, M. (2013). "Primary sensory cortices contain distinguishable spatial patterns of activity for each sense." Nat Commun 4: 1979.
Yu, Y. (2019). "Layer-specific activation of sensory input and predictive feedback in the human primary somatosensory cortex." Sci Adv 5(5): eaav9053.