Training of goal-directed attention regulation enhances control over neural processing for
individuals with brain injury. By Chen
deficits in attention/executive control are common delibating/persistent consequences of brain
OBJECTIVE: identify the neural mechanisms that underlie cognitive improvements w/rehab
training of attention regulation.
HYPOTHESIS: intensive training in attention regulation improves cog processing via
enhancement of modulatory control of neural processing in pts with acquired brain injury
- 12 pp either in standardized training design to target goal-directed attention regulation in
comparison to brief education (control cond). Training resulted in sig improvement on behavioral
measures of attention/executive control. MEAN DEMOGRAPHICS: 48 years, all had ongoing
cognitive dysfunction, difficulties in personal life functioning consistent with executive deficits,
all on stable med regimens. Brain injuries include stroke, trauma, haemorrhage, tumor resection
and chemotherapy affecting both frontal/cortical white matter regions.
- fMRI adapted for testing the effects of intervention for pts wit varied pathology were used to
index modulatory control of neural processing.
PREDICTION: enhanced goal-based modulatory control of neural processing wud be evident in
change in neural representation in visual areas (stimulus processing) and prefrontal cortex (goal-
based modulatory control).
- most common deficits after TBI are in executive functioning (paying attention, working
memory, organizing/developing efficient strategies for completing activites). These deficits
directly impede on rehab success and have poor outcomes.
- understanding the neural basis of cog even improvement, it might help develop treatments that
- selective processing of goal-relevant info: central to executive functioning, it filters wat info
gains access to more in-depth processing
- this a previous study they increased ecological validity: as the attention regulation
skills/strategies were applied in ecologically valid situations. While the experimental training
protocol (goal-management and problem solving) was previously administered to brain injured
pts/other pop, along with mindfulness-based attention regulation strategies applied to daily life
situations and complex project-based functional tasks. FOUND: pp improved on neuropsych
measures of attention/executive control while educational activity resulted in no improvements.
INTERVENTION: i) training in goal-oriented attentional self-regulation (goal training-
involved group, individual and home practice- divided into 2 parts), ii.) educational activity
(education)- 5 weeks of didactic educational instruction regarding brain injury (causes,
symptoms, and effects)
- 1 part of goal training: mindfulness-based attention regulation training- tries to reduce
distractability by getting the person identify the primary goal, divide info presented into relevant
vs non-relevant and have working memory hold on to relevant info while letting go of irrelevant;
To assist application in daily life situations pp were trained in applying a single phase (part of
mindfulness) STOP-RELAX-REFOCUS. 2 half emphasized goal management strategies. This
phase emphasized learning strategies for accomplishing individually-salient, self-generated
complex goals. They were asked trained to apply attention regulation and step wise goal
managemet strategies on individual functional goals (planning a meal) and group functional
goals (meeting plan) - to avoid repeated testing effects they included __________
- randomized to receive either the goal training or education during the first 5 week study period
and then switched over to other intervention for the nxt 5 weeks. There were 3 assessment time
periods (before pp, end of the 1 study period, and finally at the end of the 2 study period)
-scanned individuals before/after the intervention (attentions regulation vs education training)
and examined effects on a functional MRI biomarker designed to index the neural correlates of
attentional modulation. These measurements allowed them to detect neural changes on within-
subjects basis over time & measure interindividual variations in pathological damage.
- during scanning the pp performed a cognitive tasks that was based on a common situation in
everyday life where multiple streams of info compete for attention/processing. This requires
perception of all images that are each represented by a neural network, but selective processing
of some images which depends on the task goal.
- used a novel functional MRI pattern classifier method to decode the clarity of info
represented when stimuli were goal-relevant vs non-relevant.
A/ Primary analysis: quantified changes that occurred from pre to post-goals training. This
tested the hypothesis regarding effects of goal training for each of the measured variables
(behavioral improvements related to attentional self-regulation- seen by improvements on
performance on non-trained neuropsych tests of attention/executive control, transfer effects and
changes in motor speed).
- for fMRI they tested whether goal training wud enhance modulation of neural processing in
extrastriate cortex and alter processing in prefrontal cortex.
- compared changes from the pre to post-goals training with those that occurred from education.
And assessed these using a linear mixed model. This was performed under the assumption that
the education intervening wud not lead to sig behavioral/neural changes which were confirmed.
B/ stcondary study analysis: used to support the tested hypothesis
- 1 a within subjects assessment of the effects of goals training relative to multiple baseline
measurements using a paired t-tests for pp who started w/education prior to goals training.
- 2 : an across-subjects comparison of changes in each variable was performed in the 1 periodst
only (compared pre/post education with goals training), as they expected interindividual
variability to be higher than intergroup variability.
Functional MRI cognitive task design:
-all task conditions involved a series of images of 2 categories (faces and scenes), which were
intervalled using a pseudorandimzed timing order
- perceptual info was matched but task demands differed for the 4 attention conditions (2
selective attention conditions and 2 non-selective conditions).
- selective attention condition: asked to either pay attention to scenes or faces, and there was a 1-
back match (same pic presented twice in a row) they had to press a button when this was the
case. Involves pp to perceive and recognize all images but selectively maintain only relevant
images in working memory while being distracted)
- each block has 20 images (10 faces, 10 scenes) presented sequentially. Timing presentation and
image category were balanced across condition blocks and counterbalanced across pp. There
were a total 5 blocks (100 stimulus/condition). 4 conditions
Regions of interest: dorsolateral prefrontal cortex (bilateral middle frontal gyrus) and
extrastriate cortex (fusiform, para-hippocampal and lingual gyri) Functonal MRI data analysis:
---analyses of info contained in patterns of brain activity:
- cog task performed during the fMRI involved the presentation of multiple stimuli that compete
for neural processing, while only goal-relevant stimuli must be selected for further processing.
They did this using a multi-layer perceptron pattern classifier which was based on the
category of the viewed image, and served as an external reader to determine the cl