• Our minds drift away from demands of the immediate external environment to focus on
the internal milieu
o “Stimulus-independent thought”
o “Task-unrelated thought”
o Doing a task that is more mundane and simple
o Attention-grabbing stimulus is internal
o Triggered by something that is happening externally
o Something that we intentionally allow ourselves to think about
o E.g. our future goals
• Task-related attention
When one’s attention is firmly directed towards the task
o Mind wandering
When one’s attention has drifted away from the external task
• How do we measure “mind wandering”?
o Experience sampling at various intervals
Compare behavioural data of being on-task and mind wandering
o Behavioural measures of reaction times and the number of errors committed
while carrying out a task • What affects mind wandering frequency?
Older adults tend to mind-wander less than younger adults
o Individuals with personal concerns mind-wander more than others
Unfulfilled “open goals” tend to pull our attention away from on-going
o Dysphoric (mildly depressed) individuals tend to mind-wander more than those
who are not dysphoric
o People doing a non-demanding, mundane task are more likely to mind-wander
than someone who is doing a demanding, challenging task
• Mind-wandering research
o Three mains issues!
Qualitative contents of thoughts
Impact of mind-wandering on neural and cognitive processing
• Neural network of mind-wandering
o Default mode network (DMN)
DMN regions are more active during internally focused tasks and
deactivate during externally focused tasks
o The brain is not idle at rest.
In the past, researchers had assumed that at the baseline level, there
was no activity in the brain.
DMN regions are more active when the brain is “at rest” and consist of
reflecting on internal information
o Stimulus-independent thoughts (SITs) & default mode network (Masons et al.,
Research question: Is DMN implicated in mind wandering? Methods: Participants were trained on tasks so their minds could wander
when they performed practiced blocks, which were compared to novel
blocks. Production of SITs and DMN activity were assessed.
Hypothesis: Individuals should exhibit greater recruitment of the DMN
when performing tasks that are associated with a high incidence of SIT.
Results: DMN regions showed greater activity during practiced blocks
relative to novel blocks.
• DMN regions include medial prefrontal cortex + cingulate +
insula + posterior cingulate
Conclusion: DMN regions are activated during periods in which mind
wandering is most likely to occur, suggesting that mind-wandering
constitutes a psychological baseline that emerges when the brain is
o Mind-wandering and default mode network (Christoff et al., 2009)
Research question 1: Does DMN recruitment occur during the precise
moments when the mind wanders?
Research question 2: What is the role of the executive system of the brain
during mind wandering?
Methods: Participants performed the sustained attention to response
tasks (SART) in the scanner, measuring a person’s ability to withhold
responses to infrequent and unpredictable stimuli during a period of rapid
and rhythmic responding to frequent stimuli.
• Experience sampling (which asks participants to stop at certain
times during their tasks and make notes of their experience in real
time) was used to provide a measure of mind wandering
Results: Regions of the DMN (dorsal anterior cingulate cortex, ventral
ACC, precuneus, temporoparietal junction, prefrontal cortex, and insula)
were activated during mind-wandering without awareness. Similar regions
were activated during mind-wandering with awareness, but to a lesser
Key finding 1: Mind wandering was associated with recruitment of regions
that form the core of the default mode network. This recruitment is most
pronounced in the absence of meta-awareness.
Key finding 2: Mind wandering entails recruitment of the executive system
of the brain. o Thought content, activity, & mood (Killingsworth & Gilbert, 2010)
Naturalistic study, and correlational (no cause-and-effect)
Questions asked about happiness, activity, and mind wandering
Mind wandering occurs frequently (~47%)—it is ubiquitous
The type of activity did not have a huge impact on mind-wandering
People were less happy when mind-wandering than when they were not,
regardless of the type of activities (even when compared to the least
enjoyable activities), therefore making the researchers conclude that a
wandering mind is an unhappy mind.
o Thought content & mood (Franklin et al., 2013)
Asking students whether they were off-task via a PDA
Differentiated thoughts based on how interesting, useful, and novel they
Highly interesting or useful thoughts are associated with higher levels of
happiness, suggesting that the thought content influences our mood.
Result 1: Mind wandering is generally associated with lower positive
Result 2: Content of thought (during mind wandering) can enhance mood:
high-interest mind-wandering episodes are associated with more positive
mood than on-task episodes
o Sensory response (Kam et al., 2011)
Question: Do fluctuations in task-related attention attenuate sensory
inputs at a cortical level?
Sustained attention to response (SART) task: participants occasionally
reported their attentional state as they performed SART, while their EEGs
were being recorded.
Methods: measured the P1 or P100 signal (the first positive component
that occurs about 100 ms after presentation of stimulus) of the ERP in the
occipital lobe, as well as the N1 or N100 signal (the first negative
component that occurs about 100 ms after onset of stimulus) of the ERP
in the frontocentral lobe • Experience sampling prompted by a blue screen
Results: amplitudes of both P1 (visual) and N1 (auditory) were attenuated
during periods of mind wandering relative to on-task; in other words,
when we are on task, we are showing greater response to the visual and
Discussion: Both sensory responses of task-irrelevant visual and auditory
stimuli were selectively reduced during mind wandering relative to on-task
• This suggests that when our attention drifts off-task, this can lead
to transient reductions in the intensity of sensory-evoked cortical
activity across multiple sensory domains.
o Cognitive response (Smallwood et al., 2008)
Question: Are periods of mind wandering associated with reduced
cognitive analysis of the external environment?
Differentiated between tune-outs (aware of mind wandering away from
the task at the time the thought probe was presented) and zone-outs (off-
task but unaware of and surprised by having been mind-wandering away
from the task at the thought probe was presented)
Methods: measured the P3 or P300 signal in ERP that occurred in the
parietal lobe about 300 ms after stimulus onset
Results: P3 amplitudes were attenuated during periods of mind
wandering relative to on-task
Discussion: When the mind wanders, there is a reduction in the depth of
cognitive analysis of task-relevant stimuli in the external environment.