Documents
Resources
Learning Center
Upload
Plans & pricing Sign in
Sign Out

Evolutionary Psychology

VIEWS: 3 PAGES: 22

									            Evolutionary Psychology
                             Week 4

      Brains, Minds and Consciousness
Running Order ...
• Development of the brain
• Functional anatomy of the adult brain
• The mind – body problem
• The computational metaphor
• The Classical Cascade
• The intentional stance
Evolutionary Psychology
Week 4 - Brains, minds, and consciousness

Development of the brain

 Growth & development of the CNS involves ...
     Induction of the neural tube
     Neural ...
             proliferation
             migration
             aggregation & differentiation
             synapse formation
             cell death
             selection & stabilisation
Evolutionary Psychology
Week 4 - Brains, minds, and consciousness

Development of the brain

Induction of the neural tube
18 days: Ectoderm (outer dorsal layer of embryo) forms the neural plate.
21 days: The plate curls in upon itself and fuses to form the neural tube.
28 days: The tube is closed and its rostral (nose) end develops three chambers
   – later to become the ventricles – will become the fore-, mid- and hindbrain.
50 days: Symmetrical division gives way to asymmetrical division.

70 days: The tube is c1.25cm (1/2 inch) & mostly ventricle.
140 days: The tube is c5cm (2 inches) & mostly tissue.

150 days the contours of the adult brain are discernible ... .
  Evolutionary Psychology
  Week 4 - Brains, minds, and consciousness

  Development of the brain

1. Within the embryonic sac the neural tube is formed.
2. Cells inside the tube proliferate.
3. These cells divide and produce neurons properly.
4. The neurons radiate outward from the centre of the tube via glia cells..
5. The process of radiation takes neurons to different chambers of the
    developing tube at different rates.
6. The chambers become the ventricles and the neurons begin to form the
    different parts of the mature brain.
7. The first discernible parts of the brain are the Fore-, Mid- & Hindbrain.
8. Once neurons have migrated to their final destinations very few new neurons
    are produced.
9. Once neurons have migrated axons and dendrites begin to form.
Evolutionary Psychology
Week 4 - Brains, minds, and consciousness

Functional anatomy of the adult brain

• Mapping the CNS & Brain

•   Sagittal plane
•   vertical slice down the middle
•   Horizontal plane
•   horizontal slice through the middle
•   Coronal plane
•   vertical slice at 90% from the Sagittal

• Deviations are expressed in relation to
  established planes:
• lateral sagittal
• ventral coronal
Evolutionary Psychology
Week 4 - Brains, minds, and consciousness

Functional anatomy of the adult brain       • Cerebral cortex
                                             • Basal ganglia
• Forebrain             Telecephalon        • Limbic system

                                              • Thalamus
                        Diencephalon        • Hypothalamus

• Midbrain             Mecencephalon           • Tectum
                                             • Tegmentum

                       Metencephalon         • Cerebellum
                                               • Pons
• Hindbrain
                      Myelencephalon
                                               • Medulla
         Evolutionary Psychology
         Week 4 - Brains, minds, and consciousness

         Functional anatomy of the adult brain

Telecephalon Diencephalon Mecencephalon Metencephalon Myelencephalon




     •    Cere.        Thalamus          Tectum      Cerebellum   Medulla
         cortex      Hypothalamus
                                       Tegmentum       Pons
 •        Basal
         ganglia
 •       Limbic
         system
Evolutionary Psychology
Week 4 - Brains, minds, and consciousness

Functional anatomy of the adult brain
  Evolutionary Psychology
  Week 4 - Brains, minds, and consciousness

  Functional anatomy of the adult brain


• The Hindbrain
• Contains the brain
  structures below the
  midbrain. This region
  relays information from the
  spinal cord to other parts of
  the brain. It helps control
  movement coordination,
  involuntary functions and
  equilibrium, e.g. body
  temperature.
  Evolutionary Psychology
  Week 4 - Brains, minds, and consciousness

  Functional anatomy of the adult brain

• The Midbrain
• Is a collection of nuclei that
  mainly relays sensory
  information from sense
  organs to other brain areas
  and coordinates some
  reflex activity, e.g. the
  pupil.
    Evolutionary Psychology
    Week 4 - Brains, minds, and consciousness

    Functional anatomy of the adult brain

•    The Forebrain
•    Carries out the ‘highest’
     intellectual functions inc.
     negotiating others.
•    The largest section of the
     forebrain is the cerebral
     cortex a.k.a. cerebrum &
     neocortex.
•    Note:- Resembling a big
     walnut, the cerebral cortex
     makes up 70% of the nervous
     system.
Evolutionary Psychology
Week 4 - Brains, minds, and consciousness

Functional anatomy of the adult brain
 The Frontal lobe                         •   The Parietal lobe
 Damage to this lobe can effect           •   Damage to this lobe can effect
                                          •   recognition of touch and pain
 •   ability to execute plans
                                          •   the sense of where the body is
 •   ability to consider others               in space.
 •   motivation
 •   ability to execute movements.
                                          •   The Occipital lobe
 The Temporal lobe
                                          •   Damage to this lobe can effect
 Damage to this lobe can effect           •   vision
 •   recognition of familiar faces        •   face & object recognition.
 •   ability to distinguish between the
     real and imaginary
 •   Memory: esp. short term.
Evolutionary Psychology
Week 4 - Brains, minds, and consciousness



The novel aspect of EP over common-or-garden cognitive
  psychology is that it claims to know what to look for by way of
  cognitive functions, courtesy of our understanding of the
  selection pressures that brought us about.
Try it this way ...
• The structure of the body serves survival & reproduction & this
  functional structure is a product of natural selection.
• EP’s propose that cognitive structure has also been designed by
  NS to serve survival & reproduction.
  Evolutionary Psychology
  Week 4 - Brains, minds, and consciousness

  The mind-body problem

             • Dualism                   ‘I think therefore I am’
• As the term suggests, the basic idea
  of dualism is that mind and matter
  are two different sorts of entities.   Objectivity & Subjectivity
• Whilst many facets of one do not          – Privacy of thought
  appear readily translated into the        – Phenomenal qualities
  other, the most obvious property          – Intentionality
  that distinguishes them is physical
  extension.                                – Causal relations.
• i.e. physical objects occupy space,
  thoughts do not.
Evolutionary Psychology
Week 4 - Brains, minds, and consciousness

The mind-body problem

Cartesian Dualism
Descartes concluded that . . . .

1.   What we ‘know’ first and for sure is that there is mind -
     physical things are secondary.
2.   Accordingly, the physical and the mental are distinct
     ‘substances’.
Evolutionary Psychology
Week 4 - Brains, minds, and consciousness

The computational metaphor

... only it isn’t a metaphor
Cognitive Psychology takes the mind to be a computer and not just
  like a computer.


def:- computation; a set of definite processes; e.g. algorithms; that
   begin with information and produce a decision.


    i.e. stimuli is taken as content which is then manipulated
       according to specific and specifiable rules. The result of the
       manipulation is output – this can be behaviour or a further
       mental state.
Evolutionary Psychology
Week 4 - Brains, minds, and consciousness

The computational metaphor

• Computation is what is important in cognitive psychology and not
  computers.
• Computations are the programmes, computers are the machinery
  upon which programmes run, and they depend upon:
Identifiable information - the ‘system’ needs to be able to ‘see’ that a
   change outside of itself is pertinent to itself.
The ability to discriminate - it needs to be able to see what the
  information ‘means’.
The capacity for change in light of the information - the system needs
  to be able to respond in at least 1 of 2 ways.
This process need be no more complicated (?) than a thermostat, but
   may be as complicated as one cares to imagine.
Evolutionary Psychology
Week 4 - Brains, minds, and consciousness

The Classical Cascade

Try it this way ...
• Humans need to ‘solve’ the problem of edge detection.
• A property that a brain should have is an algorithm to detect edges
  in order to avoid them.
• Once we have specified such an algorithm & found that we behave
  in a manner as to suggest that we are using such an algorithm, we
  have a description of the solution to the given problem. We have a
  psychological account.
Evolutionary Psychology
Week 4 - Brains, minds, and consciousness

The Classical Cascade

Key points so far ...
• One need not know the specification of the machine on which
  programmes run in order to know the programmes themselves.
• The distinction between computations and computers, between
  hardware and software is said to hold between what we typically
  call mind and brain.


Some more terminology ...
Problems, Domains & Darwinian Algorithms
def:- domain; a type or class of problem.
def:- Darwinian algorithm; a naturally selected solution.
Evolutionary Psychology
Week 4 - Brains, minds, and consciousness

The Classical Cascade
What sort of things might constitute a ‘problem’ at the top of the
  Classical Cascade?
• Solicitation of parental assistance
• Parenting
• Modelling the spatial distribution of (food) objects
• Navigating
• Avoiding predators, food toxins, incest etc.
• Social competition, deception & manipulation
• Understanding the intentions of others
• Finding a reproductively viable mate.
Evolutionary Psychology
Week 4 - Brains, minds, and consciousness

The Classical Cascade

All of the above, and many others, constitute ‘problems’
    – if you don’t solve them you won’t enjoy RS.
The more pressing the problem is, the more intensely natural
  selection will favour variations that produce a ‘better’ solution.
It is this push toward specialisation that produces specificity of
     algorithm.
Evolutionary Psychology
Week 4 - Brains, minds, and consciousness

The Classical Cascade

Domain specificity refers to the fact that adaptations solve particular
  problems
    – i.e. the adaptation that we call the lung solves a different sort &
      type of problem to that of the eye.
Three points to note ...
• A domain is a selection pressure & selection pressure can be
  conceptualised as a reproductive problem.
• Selection pressures create adaptations, & adaptations will not solve
  problems in other domains.
• Domain specificity is a property of physiological adaptations
  presumed to be a property of psychological adaptations also.

								
To top