International Journal of Brain and Cognitive Sciences 2016, 5(1): 1-6
DOI: 10.5923/j.ijbcs.20160501.01
Influence of Attention Resource Allocation on Sequential
Swallow in Healthy Young Adults
Thejaswi Dodderi
*
, Vaz Larisa
Department of Audiology and Speech Language Pathology, Nitte Institute of Speech and Hearing, Mangaluru, India
Abstract Despite the role of central pattern generator in swallowing, till date, there exists a contributing opinion on
involvement of cortical structures. This has lead few researchers to contemplate cortical function involvement while
swallowing using behavioral experiments. Hence, the primary focus of the study was to investigate if sharing attention
resources affects swallow performance in healthy young adults. A cross sectional study design was adopted involving 30
gender matched healthy adults within 18-23 years of age. 100 ml water swallow test was administered on each subject across
two conditions. In the baseline condition, subjects continuously ingested 100 ml luke warm water directly from the rim of 120
ml capacity cup. Based on which, volume/swallow (V/S), time/swallow (T/S) and swallow capacity (SC) indices were
obtained. This task was compared with Concurrent Cognitive Task (CCT), which involved performing a cognitive task,
namely Visual Feature Scan, simultaneously with 100 ml water swallow test. On comparison, between the two conditions,
results revealed decreased V/S with longer T/S and decreased S/C for CCT condition. Statistically significant difference was
noted at 95% confidence level when one way ANOVA was applied between the two groups. Collectively the results observed
sheds light that allocating attention resources elsewhere hampers swallow performance. Thereby, highlights the existence of
overlap between cognitive control and central pattern generator during swallowing.
Keywords 100 ml, Thin Liquids, Divided Attention, Cognitive Task, Swallow
1. Introduction
Deglutition involves series of complex, co-ordinated
neuromuscular process controlled by the brainstem. Despite
researchers supporting swallow as a reflexive and/ or
automatic behavior, the overlap between higher level
processing, like cognition, and central pattern generator is
addressed recently ([1]). To define, cognition is an
unobservable mental process ([2]). The potential influence of
cognition in swallowing was conceived nearly 30 years back,
when concepts of oral preparatory phase and lingual-bolus
propulsion were rigorously explored ([3]). Owing to this, a
newly theorized anticipatory phase was proposed that
precedes the traditional four phases of swallowing ([4]).
Anticipatory phase explicitly deals with how cognition
controls our fine and gross motor neural commands before
initiation of oral phase of swallow. To specify the role of
anticipatory phase, it imparts selection of food size, type and
positioning of food into the oral cavity, all critical to trigger
sequential oral preparatory and oral phase of swallowing
([3], [4]). Since this corresponds to voluntary aspects of
swallow, that are channelled by cortical and basal ganglia
* Corresponding author:
thejaswi07@gmail.com (Thejaswi Dodderi)
Published online at http://journal.sapub.org/ijbcs
Copyright © 2016 Scientific & Academic Publishing. All Rights Reserved
neural activity, one can arrive at the conclusion that its neural
control may not completely reside at the central pattern
generator ([5]). Apparently, the efficiency of anticipatory
phase is dependent upon the amount of attention resources
allocated by an individual, thereby making it sensitive to
interference.
Over the years several researchers have addressed that,
during swallow, cortical areas get activated along with
central pattern generator. Collectively, numerous
neuro-imaging studies evidences activation of cortical areas
that associates with control over attention resources ([1], [6],
[7]). Though each technique has its boon, disadvantages like
lack of temporal sensitivity, lack of resolution, radiation
exposure and risk of seizures has led to many clinical
modifications ([8-11]). Following these evidences, but
overcoming the banes, researchers have explored with the
focus of finding an answer to the research question ‘How
cognition influences swallow?’ using behavioral tasks. This
steered the genesis of behavioral experiment “Dual Task
Paradigm” and/ or “Concurrent Cognitive Task” ([12-14]).
The primary assumption of these tasks is the shared neural
substrates, if any, will lead to decrease in either and/ or both
the tasks performance. Typically, this is monitored by
comparing isolated swallow performance with CCT. To
observe swallowing aspects, typically, one continuously
ingests a pre-determined quantity of thin liquids. This format
is followed to monitor the sequential swallow or one’s