Keyboard Shortcuts?

×
  • →Next step
  • ←Previous step
  • ↓Skip this slide
  • ↑Previous slide
  • mShow slide thumbnails
  • nShow notes
  • hShow handout latex source
  • NShow talk notes latex source

Click here and press the right key for the next slide (or swipe left)

also ...

Press the left key to go backwards (or swipe right)

Press n to toggle whether notes are shown (or add '?notes' to the url before the #)

Press m or double tap to slide thumbnails (menu)

Press ? at any time to show the keyboard shortcuts

\title {Central Themes in Philosophy \\ Lecture 03}
 
\maketitle
 

Lecture 03:

Central Themes

\def \ititle {Lecture 03}
\def \isubtitle {Central Themes}
\begin{center}
{\Large
\textbf{\ititle}: \isubtitle
}
 
\iemail %
\end{center}

Previous lecture:

What are the functions of perceptual awareness?

This lecture:

Can you perceive something without being perceptually aware of it?

 
\section{Perception without Awareness?}
 
\section{Perception without Awareness?}

‘Here lies the fatal flaw in [...] the philosophy of mind,

for, in using as evidence what seems reasonable or persuasive, philosophers ultimately rely on their own introspections.

They look inside themselves in an attempt to discover the design of the mind’

\citep[p.~380]{bridgeman2004philosophy}

Bridgeman, 2004 p. 380

We are not going to do that ...

Can you perceive something without being perceptually aware of it?

Yes : Sidis

Yes : blindsight

Sidis’ subjects are not perceptually aware of the letter but can identify and report it.

k  k  k  k

Can you perceive something without being perceptually aware of it?

Yes : Sidis

Yes : blindsight

Weiskrantz et al, figure 2

Awareness makes no measurable difference to action.

Can you perceive something without being perceptually aware of it?

Yes : Sidis

Yes : blindsight

Are we convinced by this evidence?
 

Simple Seeing

 
\section{Simple Seeing}
 
\section{Simple Seeing}

‘If psychologists can really identify something that deserves to be called perception without awareness, they must have an operational grasp on not only what it takes to perceive something, but on what it takes to be conscious of it.

\citep[p.~148]{Dretske:2006fv}

Dretske, 2006 p. 148

We need to start by clarifying what we mean by perceiving. To this end I want to introduce an old story that we will also use later (for Sense & Reference).

Siegel & Shuster, 1939 (Issue 1)

Siegel & Shuster, 1939 (Issue 1)

Siegel & Shuster, 1939 (Issue 1)

Does Lois see the unbearable coward?

Does Lois see the unbearable coward?

1. Lois sees Superman.

2. Superman is Clark.

3. Clark is the unbearable coward.

Therefore:

4. Superman is the unbearable coward.

How did I get here?

Therefore:

5. Lois sees the unbearable coward.

1. If Lois could see the unbearable coward, she’d know where he is.

2. Lois does not know where the unbearable coward is.

Therefore:

3. Lois cannot see the unbearable coward.

Simple Seeing (aka Nonepistemic Seeing)

Dretske introduces the notion of \emph{simple seeing} (see \citealp[chapter 6]{Dretske:2000ky}; the same thing is called as ‘nonepistemic seeing’ in \citep{Dretske:1969td}). The key characteristic of simple seeing: if X is the F, then \emph{S sees X} is equivalent to \emph{S sees the F}.

Key characteristic of simple seeing: if X is the F, then S sees X is equivalent to S sees the F.

\citep[p.~54]{Dretske:1969td}.

Dretske, 1969 chapter II; Dretske 2000 chapter 6

‘Seeing objects is a way of getting information about them. What makes it seeing (rather than, say, hearing) is the intrinsic character of those events occurring in us that carry the information. What makes it X (rather than Y) that we see is that the information these internal events carry is information about X (rather than Y). Everything else [...] is [...] something the scientist, not the philosopher, should provide’ \citep[p.~112]{Dretske:2000ky}.

‘If psychologists can really identify something that deserves to be called perception without awareness, they must have an operational grasp on not only what it takes to perceive something, but on what it takes to be conscious of it.

\citep[p.~148]{Dretske:2006fv}

Dretske, 2006 p. 148

We have been clarifying what we mean by perceiving.

Siegel & Shuster, 1939 (Issue 1)

Can you perceive something without being perceptually aware of it?

The question is trivial if we interpret ‘perceive’ so that this (Lois’ seeing superman but not being aware of the unbearable coward) counts as a case of perceiving without awareness.
To make this question hard, and therefore interesting, we need to understand ‘perceive’ in the sense of simple seeing.

‘Perception without awareness [...] is therefore to be understood as perception of some object without awareness [...] of that object’

Dretske, 2006

\citep{Dretske:2006fv}.
Note that we have not attempted to discover the design of the mind, merely made a distinction.

‘Here lies the fatal flaw in [...] the philosophy of mind,

for, in using as evidence what seems reasonable or persuasive, philosophers ultimately rely on their own introspections.

They look inside themselves
in an attempt
to discover the design of the mind’

\citep[p.~380]{bridgeman2004philosophy}

Bridgeman, 2004 p. 380

 

A Test for Perception?

 
\section{A Test for Perception?}
 
\section{A Test for Perception?}

‘If psychologists can really identify something that deserves to be called perception without awareness, they must have an operational grasp on not only what it takes to perceive something, but on what it takes to be conscious of it.

\citep[p.~148]{Dretske:2006fv}

Dretske, 2006 p. 148

We have been clarifying what we mean by perceiving in terms of simple seeing.
But can we go further and give a ‘test for perception’?

blindsight:

infer perception from discrimination of visual stimuli

This was the point of talking about simple seeing.

You must have got information about the thing

But: allergic reactions to ragweed
What does it take to perceive something? By what test could we measure whether someone has perceived a particular object? According to Dretske, to perceive an object: \begin{itemize} \item you must have got information about the thing; and \item ‘the information in these states should be available for the control and guidance of action’; and \item ‘the information should be extracted from stimulation [...] by accredited receptor systems’ \citep[p.~150]{Dretske:2006fv}. \end{itemize}
Note Dretske’s qualification: ‘Even with the additional qualifications [not specified here], this ‘test’ for perception of an object is not going to withstand philosophical scrutiny---too many loose ends and philosophically troublesome qualifiers’ \citep[p.~151]{Dretske:2006fv}.

and ‘the information in these states should be available for the control and guidance of action’

and ‘the information should be extracted from stimulation [...] by accredited receptor systems.’

Dretske, 2006 p. 150

 

Operationalising Perception and Perceptual Awareness

 
\section{Operationalising Perception and Perceptual Awareness}
 
\section{Operationalising Perception and Perceptual Awareness}

‘If psychologists can really identify something that deserves to be called perception without awareness, they must have an operational grasp on not only what it takes to perceive something, but on what it takes to be conscious of it.

\citep[p.~148]{Dretske:2006fv}

Dretske, 2006 p. 148

blindsight:

infer perception from discrimination of visual stimuli

This was the point of talking about simple seeing.

we infer lack of awareness from the subject’s reports

 

Operationalising Visual Awareness

 
\section{Operationalising Visual Awareness}
 
\section{Operationalising Visual Awareness}

‘If psychologists can really identify something that deserves to be called perception without awareness, they must have an operational grasp on not only what it takes to perceive something, but on what it takes to be conscious of it.

\citep[p.~148]{Dretske:2006fv}

Dretske, 2006 p. 148

blindsight:

infer perception from discrimination of visual stimuli

This was the point of talking about simple seeing.

we infer lack of awareness from the subject’s reports

x

Task 1 : Say when you can see which letter it is.

Task 2 : Guess the letter (forced choice).

Task 1 vs Task 2 : example of biased vs unbiased response

Ready? Go!

Group 1: £10 if you answer correctly, -£1 wrongly

Group 2: £1 if you answer correctly, -£10 wrongly

shifting criteria. A point made by \citet{cowey:2010_blindsighta} and Phillips

‘If psychologists can really identify something that deserves to be called perception without awareness, they must have an operational grasp on not only what it takes to perceive something, but on what it takes to be conscious of it.

\citep[p.~148]{Dretske:2006fv}

Dretske, 2006 p. 148

blindsight:

infer perception from discrimination of visual stimuli

we infer lack of awareness from the subject’s reports

conclusion

In conclusion, ...

Can you perceive something without being perceptually aware of it?

Sidis’ 1898 results, and blindsight, appear to imply you can.

But drawing this conclusion requires us to accept implicit assumptions about the operationalisation of perception and perceptual awareness:

What does it take to perceive something?

What does it take to be conscious of something?