Dr. Mark Ashton Smith, Department of Psychology, Bilkent University

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1 UMAN CONSCIOUSNESS some leads based on findings in neuropsychology Dr. Mark Ashton Smith, Department of Psychology, Bilkent University

2 nattentional Blindness Simons and Levin, 1998

3 Not Detected Detected Rensink et al. 1997

4 We are surprisingly unaware of a lot of our perceptual environment if it is not central to the goals we are attending to.

5 ITUATION MODEL THEORY Developed from discourse comprehension (Zwaan( & Radvansky,, 1998; ; recently Jeffrey Zacks work ) Readers and viewers construct mental models (situation models) that segregate experience into meaningful events.. Events are defined by the locations of agents and their goals, and causal interactions. Changes of characters or character goals > change of event > update model

7 Event Segmentation

8 vent Structure Perception People perceive activity as a series of discrete meaningful events (e.g. open ironing board, plug in iron, get shirt ) Knowledge of event structure becomes increasingly elaborated throughout life. Knowledge of event structure is used in remembering, planning and reading. Event segmentation is predictive of later memory.

9 Human brain activity time-locked to perceptual event boundaries. Zacks,, et al. (2001) Nature Neuroscience 4,, Is the human perceptual system sensitive to event segmentation during visual perception? If so, how does the brain accomplish this segmentation?

10 Functional Magnetic Resonance Imaging (fmri( fmri) ) study a. Passive viewing of movie b. Active event segmentation coarse grain fine grain Brain imaging revealed a network of 8 brain areas consistently activated during the perception of boundaries between meaningful events. Including motion area MT, the pre- motor cortex and the medial parietal lobe (precuneus( precuneus)

11 Explicit report

12 Authors Interpretation activity was modulated by the top-down influence of internal event representations information about goals, plans and causes may be integrated with physical cues to direct ongoing perceptual processing this goal understanding is mediated by areas involved in intentional motor planning and action

13 Goal directed visual guidance of action Recognition/ classification Object Recognition/ identification classification

14 anguage-based narratives? Is the human cognitive system sensitive to event segmentation during reading of narrative texts? If so, how does the brain accomplish this segmentation? Same lab with same fmri methodology using texts, not movies.

Results The event boundary network is a large subset of the visual perception event boundary network Same subset active when reading coherent stories vs unrelated sentences.

15 Results The event boundary network is a large subset of the visual perception event boundary network Same subset active when reading coherent stories vs unrelated sentences. Active areas: motion area MT, the pre-motor cortex and the medial parietal lobe (precuneus( precuneus) Human Brain Activity Time-Locked to Narrative Event Boundaries Speer et al. (2007) Psychological Science 18 (5),

16 The narrative mind this process of segmentation is part of a larger, modality-independent independent system involved in the comprehension of everyday activities involved in comprehending real-world visual events as well as narrated descriptions of those events. this similarity between processing of visual and narrated activities may reflect the existence of a general network for understanding event structure (Speer et al)

17 Out of what does this narrative event perception system evolve?

18 irror neurons mirror Insights from neurophysiology research

I I predict that mirror neurons will do for psychology what DNA did for biology: they will provide a unifying framework and help explain a host of mental

19 I I predict that mirror neurons will do for psychology what DNA did for biology: they will provide a unifying framework and help explain a host of mental abilities that have hitherto remained mysterious and inaccessible to experiments. VS Ramachandran,, Director for the Center of Brain and Cognition, University of California

20 Pre-motor and posterior parietal corte neuron responses in the Macaque a) Observed action b) Executed action Only when movement has a purpose (is an action) Specific to action type (pick up or move peanut) Respond to implied actions Rizzolatti and Gallese (1996,2001)

21 AGENT TARGET BEHAVIOUR (perceived or executed) INTENDED GOAL (implied or attained) MIRROR NEURON SYSTEM embodied simulator of targeted action

22 COMMUNICATIVE MIRROR NEURONS The mirror neuron system for action in Macaques is activated both by a. object-related actions b. communicative gestures (Ferrari et al. 2003)

23 Macaque pre-motor and posterior parietal mirror neuron areas Homologous Human MNS - Buccino et al. (2001 These are the same areas active in causal narrative event perception in humans

24 Embodied attunement Direct action understanding Non-inferential, pre-linguistic understanding of others goal directed actions and intentional gestures through motor imagery (= embodied simulation). Observed action in another > understanding of their goals

25 Language evolved from gestures, not vocalizations Free manual gestures are only found in apes and humans. Gestures are population specific. Right hand bias in both apes and humans. Ape homolog of human Broca s area is activated in production and perception of gestures but not vocalizations: Part of the ape MNS (premotor( cortex) Enlarged in apes left hemisphere. Enhances information transfer and retrieval in humans.

26 Chimpanzee and bonobo gestures 31 distinct manual gestures 18 facial-vocal gestures Begging for food a dominant has taken from him Ape gestures and language evolution. Pollick & de Waal (2007)

28 Summary so far Event perception in the narrative mind in both visual perception and language comprehension orginated in embodied attunement mirror neuron systems (MNS) like those found in apes. The MNS is designed to detect goal-directed intended actions (through simulating them in the body).

29 self vs other Mirror neuron systems need to distinguish the self and its actions (agency) from others and their actions! How does it do this? Topic Related to simulation-simulation accounts of Theory of Mind (ToM( ToM).

30 Ruby & Decety (2001) Nature Neuroscience 4,, PET brain imaging study on the effect of perspective taking on the neural network engaged during mental simulation of action. Action simulation through imagery Condition A: First person perspective Condition B: Third person perspective

31 Overlapping MNS areas and precuneus activated in both 1 st person and 3 rd person conditions. Areas distinguishing self generated action from others actions? right inferior parietal somatosensory corte fronto-polar cortex precuneus Brain areas activated by third vs first person perspective.

32 the precuneus (medial posterior parietal cortex)

33 Ruby & Decety Hypothesis 3 rd person perspectives involve heightened precuneus activity in particular: the precuneus is involved in maintaining a representation of the self. So as not consciously to confuse third-person simulation with first-person simulation, regions that are critical for body schema or self awareness may be highly recruited. Thus perspective taking ability requires selfawareness.

34 Right parietal cortex brain damage (prob. including the precuneus) ) > individual believed that his body was being controlled by external forces. I I have no thoughts; my mind is empty; I feel hypnotised PET experiment on neural correlates of hypnosis, found decreases in precuneus characteristic of this unconscious state. Self vs non-self judgments (face pictures or personality trait words) > precuneus activation only for self judgements.

35 Converging evidence (Vogeley( and Fink, 2003 ): the precuneus is involved in representing the first person perspective (the viewpoint of the observing self) and interpreting an action as being controlled by oneself versus another person.

36 Shared Circuits Event Segmentation in narrative reading and perception Critical area in both circuits: the precuneus Self other differentiation a subset of event perception areas

37 Precuneus neuroanatomy and physiology More highly developed (i.e. a larger proportion of the brain volume) in human beings than in non-human primates or other animals. Most complex columnar cortical organization of all cortical areas. Among the last regions to myelinate in ontogeny. Highest resting metabolic rate among brain areas - consuming 35% more glucose than any other area of the cerebral cortex in humans, and other species.

38 recuneus & consciousness Cavanna & Trimble (2006). Brain, 129(3): Precuneus most active in the resting, alert brain. Involved in: retrieval / consolidation of autobiographical memory, Explicit processing of information (mental images / spontaneous thoughts) Manipulation of this information for problem-solving and planning. Enhanced consciousness state of yoga meditation > precuneus- prefrontal core. High level of reflective self-awareness > precuneus-prefrontal prefrontal core. Subliminal vs supraliminal word presentation: precuneus-prefrontal prefrontal activation only when conscious awareness of stimuli. The joint activity of precuneus and pre-frontal areas needed for task-elicited and steady state awareness.

39 ltered states of consciousness The precuneus and prefrontal cortices are significantly less active than the rest of the brain during both SWS and REM sleep. During hypnosis decreased activation in the precuneus was of key significance. During general anaesthetic infusion > decrease in precuneus associated with slipping into unconsciousness. The precuneus is one of the first regions of the brain to resume activity when regaining consciousness from a vegetative state. The precuneus and adjacent posterior cingulate cortex are the brain regions that differentiate patients in minimally conscious states from those in vegetative states

40 Conclusions Conclusions precuneus is part of a recently evolved neural The precuneus is part of a recently evolved neural network subserving self-awareness and conscious experience. In association with prefrontal cortices, this system underlies not just conscious awareness but awareness of agency - in action and in thought. This human consciousness network evolved out of earlier mirror neuron systems involved in perceiving intentional actions (both object-focused and communicative) in a social context. Mirror neuron systems have only been found in apes and monkeys thus these may be the only non-human animals capable of conscious awareness if at all.

41 Implications Consciousness may be best understood as a type of self- awareness. Consciousness may be best understood in the context of intersubjective perspective taking of mind reading in a social context. Consciousness may best be understood as having an origin in embodied simulation of others intentions both in action and communication.

DEDICATION Susan Hurley Professor Susan Hurley, Philosopher. Born on September 16, 1954.

42 DEDICATION Susan Hurley Professor Susan Hurley, Philosopher. Born on September 16, She died on August 16, 2007, aged 52 the self does not lurk hidden somewhere between perceptual input and behavioural output, but reappears out in the open, embodied and embedded in the world

Giacomo Rizzolatti - selected references

Giacomo Rizzolatti - selected references 1 Rizzolatti, G., Semi, A. A., & Fabbri-Destro, M. (2014). Linking psychoanalysis with neuroscience: the concept of ego. Neuropsychologia, 55, 143-148. Notes: Through