Download Executive function and speech-in-noise perception - the role of inhibition V. Stenbäck

Executive function and speech-in-noise
perception - the role of inhibition
V. Stenbäck1, 3, M. Hällgren3, 4, B. Lyxell 2, 3, B. Larsby 1, 3
Technical Audiology/IKE, Linköping University, Sweden.
2
Department of Behavioural Sciences and Learning, Linköping University, Linköping, Sweden.
3
Linnaeus Centre HEAD, Linköping University, Linköping, Sweden.
4
Department of Otorhinolaryngology/Section of Audiology, Linköping University Hospital, Linköping, Sweden.
1
[email protected]
Introduction and aim
Participants
In settings where a listening task is difficult, individuals use both their
hearing and cognitive abilities to process the auditory information. Little is
known about the relation between the ability to inhibit irrelevant information
and perceiving speech-in-noise and the effects of hearing loss and ageing
on this relationship. Executive functions are of importance when listening
to speech-in-noise. We use different executive functions i.e. inhibition
to focus on the relevant information and at the same time inhibit the
processing of irrelevant information.
14 normal hearing participants. 11 women and 3 men, mean age 25.3
years (SD = 4.8).
The aim of this study is to increase theoretical knowledge regarding
the relation between age, executive functions, such as inhibition, and
perceiving speech-in-noise.
• Two auditory tests of inhibition, the Hayling task and a dichotic
listening task. The Hayling task is an instrument were the participant
is to complete sentences in 3 lists with either a logical word (List 1),
as a measure of initiation, or a grammatically correct but semantically
incorrect word (List 2 and 3), as a measure of verbal inhibition. The
dichotic listening task is simultaneous stimulation of different speech
sounds in both ears, the participant is to report freely from both ears or
forced from either right or left ear.
Procedure
The participant was seated in a sound attenuated booth. The test battery
was administered in the booth or in the room. The equipment included
head phones (TDH-39), microphone for talk back function, and response
buttons on a keyboard for yes and no responses. The participant was
informed that reaction times were measured and were asked to respond as
quickly as possible.
Pearson correlation analysis and repeated measures ANOVA was used to
analyse test performances.
Methods
• Pure tone audiometry (hearing threshold levels ≤ 20 dB HL in the range
125 HZ to 8000 Hz).
• A speech-in-noise test, using Hagerman sentences, with steady-state
speech-shaped noise, targeting 50% and 80% speech intelligibility.
• A visual test of working memory capacity, the Reading span test (RS).
• A visual test of inhibition, the Simon task.
• Two visual tests of lexical access and vocabulary, the Lexical access
test and F-opposites.
Preliminary results
Correlation between Hayling inhibition lists
R2 Linear = 0.693
7
Regression
95% confid.
Low RS
High RS
6
Hayling mean reaction time (seconds)
Hayling mean reaction time, List 2 (seconds)
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Hayling lists and working memory capacity
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2
5
4
3
2
1
0
0
0
2
4
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Hayling mean reaction time, List 3 (seconds)
Figure 1 A significant correlation between mean reaction times for correct answers in
the two inhibition lists (List 2 and List 3) was found (r = .83, p < .001).
This correlation indicates that List 2 and List 3 measure the same thing, i.e. inhibition.
List 1 was developed to measure initiation, while List 2 and List 3 were developed to
measure inhibition. Consequently, no correlations were found between List 1 and List
2, nor between List 1 and List 3.
1
2
3
Hayling task list
Figure 2 An effect of Lists on reaction time was found (F(2,24) = 44.85,
p < .001). Post hoc tests with Bonferroni correction for multiple comparisons showed
a significant difference between List 1 and List 2, and between List 1 and List 3 (both
ps < .001), but no significant difference was found between List 2 and List 3.
When median split of RS was entered in the ANOVA as a between group factor, a
main effect of RS was found (F(1,12) = 11.81, p < .05) where high RS performed
better than low RS.
Preliminary conclusions
Further investigations
• Hayling lists 2 and 3 were strongly correlated which indicated that both
lists are suitable as a measure of verbal inhibition.
• The preliminary results show a significant correlation (r = .62, p = .02)
between Hayling List 1 and Hagerman speech-in-noise targeting 50%
speech intelligibility. However, no correlations were found between
speech-in-noise performance and the inhibition lists, List 2 and List 3.
One possible explanation for this might be that Hayling List 1 assesses
initiation and not verbal inhibition, and the noise type contains no
semantic information. Consequently no semantic information need be
inhibited. However, these relationships will be further investigated using
additional noise types.
• Persons with a higher working memory capacity tended to have shorter
reaction times than those with lower working memory capacity. This
suggests that having a greater working memory capacity facilitated
the cognitive processes involved in verbal inhibition, List 2 and List
3. Further more, this ability seemed to be of minor importance in the
initiation condition, List 1.