Consciousness

• seCtIon tHRee: BoDY AnD WoRLD
  open meditation bias processing towards
  goal persistence and cognitive flexibility
  respectively (e.g. Colzato et al., 2016).
  More generally, there is accumulating evi-
  dence that meditation and self-reported
  mindfulness enhance processing speed
  and cognitive flexibility and reduce sus-
  ceptibility to cognitive interference (Moore
  and Malinowski, 2009). For example, Ger-
  man psychologist Peter Malinowski (2013)
  reviewed evidence that meditation training
  leads to attentional resources being used
  more efficiently and flexibly. Many studies
  on meditation and attention use the Stroop
  word–colour task, where people have to
  name the colour of the font a word is pre-
  sented in. Normally, when there is a conflict
  (e.g. the word ‘red’ is presented in green), peo-
  ple are slower to respond, or make more errors if forced to respond quickly. Med-
  itators have been found to perform significantly better than non- meditators on
  this task, and even short mindfulness training sessions can make a difference. This
  suggests that meditation reduces automaticity and thus improves attentional con-
  trol. In one study, participants were given a raisin to eat. Those who received brief
  guidance in how to monitor their sensory experiences of eating it were better at
  detecting unexpected distractors during a goal-directed task (Schofield, Creswell,
  and Denson, 2015). Interestingly, although mindfulness is often suggested to help
  combat the effects of stress, in this experiment it did not offer any protective effect
  against ‘cognitive depletion’. Regardless of the raisin-eating training, being cogni-
  tively depleted by a difficult writing task made people more likely to process the
  perceptual details of the distractor rather than returning to the task at hand.
  Meditation research also taps into a growing interest in the activities of the rest-
  ing mind. In 2001, neurologist Marcus Raichle and his colleagues were conduct-
  ing experiments that required participants to concentrate on a demanding task.
  Such experiments commonly use a resting condition as a control, assuming this is
  uninteresting, but Raichle noticed that during the task, activity in certain areas of
  the cortex was reduced and then increased again between tasks. There seemed
  to be ‘an organized, baseline default mode of brain function that is suspended
  during specific goal-directed behaviors’ (2001, p. 676). This is how they acciden-
  tally discovered what they termed the ‘default mode’.
  The default mode network (DMN) is active when someone is awake but not
  focused on a specific task, such as during mind-wandering or daydreaming.
  Mind-wandering, or ‘task-unrelated thought’, tends to include thinking about one-
  self or other people, and remembering the past or imagining the future. Activity in
  this network is negatively correlated with other brain networks, especially those
  involved in focused attention. Major DMN hubs include the posterior cingulate
  cortex (PCC) and the medial prefrontal cortex (mPFC). The PCC is thought to be
  involved in continuous broad-based sampling of external and internal environ-
  ments when focused attention for task-specific activity is not required. The mPFC
  plays a role in mediating the visceral and motor aspects of emotional information,

%

100

Controls

Initial

baseline

Ongoing

baseline

Meditation

state

Meditation vs. rest

45

0

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%

100

Controls Practitioners

Practitioners

45

0

(a)

%

80

Ratio gamma/alpha power

40

0

(b)

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FIGURE 7.8 • (a) The ratio of gamma (25-42
Hz) to slow oscillations (4-13 Hz)
averaged within individuals across
all electrodes during compassion
meditation. The X-axis represents
the participant numbers; the Y-axis
represents the difference in the
mean ratio between the initial
state and meditative state. (b)
The significant interaction between
group (practitioner, control) and
state (initial baseline, ongoing
baseline, and meditation state)
for this ratio. The relative gamma
increase during meditation was
higher in the post-meditation
session. In the initial baseline,
the relative gamma was already
higher for the practitioners than
the controls and correlated with
the length of the long-term
practitioners’ meditation training
through life (from Lutz et al.,
2008).