C85 Lecture 1 PDF

Lecture 1 Course Overview Chapter 1- Psychology and History Chapter 2 – Touchstones: The Origins of Psychological Thought VIGNASH THARMARATNAM  don't "need to read the textbook but it's there for reference/another way to explain material; all...

Lecture 1 Course Overview Chapter 1- Psychology and History Chapter 2 – Touchstones: The Origins of Psychological Thought VIGNASH THARMARATNAM  don't "need to read the textbook but it's there for reference/another way to explain material; all questions for exams are from bullet points on slides Course Overview practice questions -> under assignments for 'Midterm' and 'Final Exam' along with breakdown by week/chapter of how many questions  Course Instructor: Vignash Tharmaratnam ([email protected])  TAs: Sherry Huang ([email protected]) Aqsa Zahid ([email protected])  Course Mark Breakdown 60-70 M/C for the midterm and nal  Term Paper Outline (5%): Rough outline of arguments and references to be used for the term paper – Due June 17th  Midterm (40%): All multiple choice questions on lecture and readings assigned for the first half of the course Ai related topic? not Rationalism  Term Paper (15%): 4-6 page argumentative essay debating the impact of rationalism and empiricism on psychology – Due July 26th  Final Exam (40%): All multiple choice questions on lecture and readings assigned for the second half of the course  For ALL Course Questions/Accommodations: [email protected]  Check syllabus for more details about the course! Q: Practice Questions for Exams? Chapter 1 - Psychology and History  Person vs. Zeitgeist  Historiography- the ways in which historians have written history and make sense of subject matter  Two approaches to history isn't there a  A) role of certain person – the original contributions an risk of erasure individual makes on society (old history bias) of non-  B) role of zeitgeist – “spirit of the times” – the hegemonic movements prevailing ideologies and socioeconomic conditions then, which that shape ideas (new history bias) can then  Darwin’s contributions perhaps could have impact action occurred from his contemporaries if not him as a society specifically was this also occurring alongside the rising popularity of later on? Rationalism and Enlightenment though?  Edwin G Boring (1886-1968)- focused primarily on growth of scientific and experimental side of psychology and individual accomplishments, while trying to acknowledge historical context Ixion’s Wheel or Jacob’s Ladder  Frank Manuel – two constructs:  A) Progressive – history moves either to a fixed end or to an indefinite end that defines itself in its course of progression History is novelty creating and always variant Jacob’s ladder: in the Bible, Jacob “dreamed that there was a ladder set up on the earth and the top of it reached to heaven”  B) Cyclical – eternal recurrence of ideas no actual progress; just looking at an idea in a new way Ixion’s Wheel: in Greek mythology was condemned to rotate on a wheel of fire Ixion’s Wheel or Jacob’s Ladder Frank Manuel – two constructs: Spiral may be better interpretation, ideas recur, but at higher and higher levels of understanding  “Modern thinkers have the advantage of time and can choose prototypes from a greater array of models”  Sheer accumulation of examples becomes an advantage even though nature is no more prolific revisiting topics where we look at it with a better foundation of knowledge (ie. theories, tested, etc.); more advantage now = natural to have progress bc of better knowledge even if the conditions (ie. feasibility for scientists to develop theories compared to the past) don't contribute to it New History of Psychology  Laurel Furomoto – coined “a new history of psychology”  Scientists operate subjectively under the influence of extra-scientific factors -> ie. focus on cancer research  Science doesn’t clearly progress from science to truth but from one world view (paradigm) shift to another  Paradigm: a set of fundamental beliefs that guide workers in a scientific discipline  Elazar J. Pedhazur - The facts may not speak for themselves because different theories can all be consistent with the same data  Fighting against confirmation bias – tendency to search for, interpret, favor, and recall information in a way that confirms or supports one's prior beliefs or values TB example Paradigms in Psychology  N.R. Hanson: bird-antelope gestalt image  Beak of a bird verses horns of an antelope  Each of the theories suggests a different interpretation of the same fact, what about ifwith the photo both wastheories upside down -> howequally being does that work with these with consistent theories? the data  The theoretical context within we interpret data determines how the data is seen need to be objective as a scientist to not have bias in uence interpretation: but is it even possible, if humans naturally are subjective in their interpretation and there isn't anyway to tell what's actually true? would it be better to acknowledge bias/the existence of other perspectives but not trying to label one or the other as objective/fact?  model drift -> thinking about something in a Paradigms in Psychology new way of thinking/through a new theory model crisis -> decide between two theories or methods model revolution -> choosing between the two;  Thomas Kuhn (1922-96) wrote “The a lot of the time, the old one prevails because Structure of Scientific Revolutions” of people's con rmation bias  During long periods of time workers in a field have the same beliefs about methods, data and theory  Establishing a single paradigm means that the discipline of interest becomes a “normal science” trying to make psychology and establish it as a normal science  United view on suitable problems and methods  At certain critical junctures,  Therefore, some data and findings may radical upheavals occurs and inevitably illegitimate paradigms shift towards new  Paradigm clashes: when there is more than one ideas paradigm to explain the same phenomenon physical world changes in psychology (unlike with chemistry/bio/physics observations) even when neutral stimuli are present because people can perceive things di erently (ie. being colourblind)  Paradigms in Psychology  Paul Feyerabend: horizontal line triangle example  What is legitimate data to support one theory might not be legitimate data that support another theory  Theories will tend to have overlap in the phenomenon they attempt to explain but each theory tends to specialize in certain phenomena and neglect others (either in part or entirely) ex. theories of lifetime (babies to old age) vs smaller time span (babies to early childhood)  No theory extends to entire range of phenomena  E.g., Behaviourists do not care about data from introspection  Different theories compete to explain the same data Examples of Major Paradigm Shifts in know these decently well Science  The transition in cosmology from a Ptolemaic cosmology (Earth is centre of the universe) to a Copernican one (Earth revolves around sun)  The acceptance of Antoine Lavoisier's theory of chemical reactions and combustion (discovery of oxygen’s role in combustion) in place of phlogiston theory (fire-like element called phlogiston in combustible bodies), known as the chemical revolution  Charles Lyell’s theory of uniformitarianism to explain geological changes on Earth over time supplanting the theory of catastrophism  The revolution in origin of humankind as being fixed in nature to Charles Darwin’s theory of natural selection  The development of quantum mechanics (objects have both particle and wave-like properties), which replaced classical mechanics (behaviour like particles) at microscopic scales  The transition between the worldview of Newtonian physics and Einsteinian general relativity.  The acceptance of Alfred Wegener’s theory of plate tectonics and continental drift as the explanation for large-scale geologic changes.  Feminism and Psychology  Seminal works on feminism such as The Second Sex (1949) by Simone de Beauvoir and The Feminine Mystique (1963) brought the perspectives of women into contemporary culture, including psychology most of psychology up to 1900s, feminist perspectives weren't taken into account -> was it that they weren't taken into account or whether they were erased (even ones that Wanted to address how female contributions prior due to the gender expectations in the 1800s) existed were being neglected by previous historians  Ex. Christine Ladd-Franklin (colour vision), Mary Calkins (memory paired associates method) Feminism and Psychology  Second generation female psychologists (received PhD 1906-1945) had their own challenges within academia  Although most were able to rise to senior ranks in academic positions, most tend to cluster in more “female” fields (e.g. developmental, clinical, educational)  ¾ married with 40% with children, had to struggle finding work-life balance while being expected to take care of household many were married to husbands within psychology  Anti-nepotism laws made it hard to hire husband and wife psychologists, leaving wives to often settle for more inferior positions (e.g. Eleanor Gibson, eminent developmental psychologist) how do biological di erences (and their scienti c knowledge throughout time) play into these models? -> example -> hormones in brain during menstrual cycles; would they be included in neuroscience? Feminism and Psychology technological evolution in biological/biochemical elds also enable more biological based theories/observations  Meredith Kimball – feminist psychologist  Two approaches to psychologist with respect to feminism  A) Emphasize psychological similarities between genders while discounts differences (e.g. Leta Hollingworth)  B) Psychological aspects that symbolically fit a more feminine perspective have been neglected and should be highlighted  Sense of connectedness, concerns with human relationships, care-giving  Evelyn Fox Keller – argued that traditional accounts of science tend to ignore factors such as intuition, empathy, and personal engagement, and social processes  Argued that science-gender system exists, where your gender influences the interpretation of science  Although “masculine” science (hard facts, statistics) is important, acknowledging social, political, and emotional influences are also Social Constructionism  Kenneth Gergen - psychology is not a simply objective accumulation of knowledge but also driven by social processes  Social construction is a dialectical process where opposing tendencies  A) Exogenic – external factors as a main determinant of human experience (e.g. British empiricists, like John Locke)  B) Endogenic – internal inherent tendencies to think, categorize, and process information as main determinant of human experience (e.g. Immanuel Kant) Social Constructionism  Psychological Research as a Social Constructionism  Jill G. Morawski, Henderikus J. Stam Research depends on the research community’s customs, ethics, economics, policy interests, and even fads  Kurt Danziger - “no such things as a private science” Social norms and the products of specific historical conditions regulate psychological research ie. no grants One needs to be sophisticated enough to recognize fads, and social biases that exist to improve the more technical contributions psychology offers Social Constructionism  Psychological Research as a Social Constructionism  John D. Greenwood Can be both social influence and “objective” truth  Many theoretical models are socially constructed since their meaning is defined by conceptual ideas  Ex. Watson and Crick didn’t see DNA’s double helix directly, it’s a theory social constructed from discussion, research and consensus agreement of data more so created from social discourse between scientists before technological methods could be used  Been socially created doesn’t discredit the theory’s factual description of DNA’s structure, or make the case that DNA as a physical entity is socially constructed if a theory can't be supported with physical evidence at the time but does later on, not discounting it because it was constructed from social discourse and as such, is subjective Reconciling Old vs. New Histories  George W Stocking and Herbert Butterfield Presentism – evaluating the past primarily in terms of the relevance to present knowledge and circumstances Historicism – “understanding the past for its own sake”, without being passéist Explaining social and cultural practices (including ideas and beliefs), by studying their historical context by which they came about  Reconciling Old vs. New Histories  A balanced approach allows us to use contemporary knowledge to help explain the past, and vice-versa  Guard against not being to critical of the past, but respect the groundwork laid by other given their circumstances  Old history – individual bias, new history – historical bias  Dean Keith Simonton – historiometric method tried to standardize the measure of looking at a person's impact over time and why (factors) that might be  Trying to capture both the individual and historical context to measure quantitatively with statistical procedures what makes someone great  E.g. Effect of lifespan, IQ, pessimism, creativity, simultaneous discoveries of scientific laws on eminence idea of people making in uential progress bc of having something in childhood to overcome, having an issue they want to resolve, and deviating from traditional education Chapter 2 – Touchstones: The Origins of Psychological Thought Pythagoras (570- 495 BC)  Although experiences are many and varied, they are united and structured by mathematics order and patterns to thoughts; not just random -> he used math to structure and group those -> he proposes one can then find order in perception through mathematics  Pitch of sound is correlated to weight of hammer, and length of strings on musical instrument  Virtue of unity and wholeness through harmony  balancing pairs opposites of experience like good/bad, light/dark, good/evil  this harmony generates the forms of life we witness, and the psyche (soul) seeks this harmony relates to Gestalt psychology  Pythagoras (570- 495 BC)  Limited vs. Unlimited  Limited – everything we can perceive, bound by inherent limits, created by an integration of opposites that stem from an original unity *go over what original unity is  Represented symbolically with odd numbers  Unlimited – everything we don’t experience, boundless phenomena  e.g. the shape of snowflakes can technically be any shape (unlimited) but since they follow geometric patterns from the laws of chemistry, they only have specific patterns we can see (limited)  Represented symbolically with even numbers for each even number, you have a corresponding opposite number (corresponding limited to each unlimited) Pythagoras (570- 495 BC) go over TB for this too Union of limited and unlimited produce all sensible phenomena 1 acts an “even-odd” since adding it to numbers changes it from even to odd or vice-versa, symbolically represents wholeness Pythagorean Mathematics  Pythagorean Theorem – 𝑎 +𝑏 =𝑐  One of the first instances where mathematical formula could be applied to physical world via geometry  Proportions of the right angle triangles were typically whole rational numbers  Problem of the irrational  Unable to solve exact values for certain numbers (1,1, 2), 𝜋, seemed like irrational numbers were an unavoidable part of reality even though their existence was known about  don’t really need to Pythagorean Mathematics know the diagram, but knowing (the math) helps to understand and remember  Irrational numbers later explored with the golden 𝟓−𝟏 ratio no real explanation why of why certain patterns are more appealing than 𝑩=𝟏 𝑨= 𝟐 others, even biologically (possibly natural selection?)  =  1: = 1: 0.618 → = 1.618.. 𝟓  : 1 = ~1.61: 1 → = 1.618 𝟐 𝟏  Claimed to be the most beautiful, “perfect” proportion, reoccurring in nature in plants animals and humans (could just be coincidence) 𝟏 𝟏 irrational number is related to our perception of beauty (faces, plants, and more) 𝟐 𝟐  Fibonacci numbers (0, 1, 1, 2, 3, 5, 8, 13, 21, 34, 55, 89, 144…) 𝟓  Start from 1 and create the following number by adding the 𝟐 previous two  Increases in values by approx. the golden ratio 𝟓+𝟏 𝑨+𝑩= 𝟐 Video explains in more detail: https://www.youtube.com/watch?v=c8ccsE_IumM know the bullet points; not necessarily need to know the math just look at the mf recording later for the explanation :)  was a rationalist Plato (427-347 BC) all knowledge exists within our souls; don’t learn but instead re-remembering what the soul knew/learnt? that existed from past lives  Perfect forms exist that are “more real” than imperfect forms we experience through our senses  Cave analogy - fire projects shadow of images on wall  the shadow: our reality and what we see  perfect form: the actual object have to undergo introspection, reflection and reasoning to understand knowledge in a more pure way to figure out the perfect form soul’s knowledge works under the assumption that humans lived infinitely into the past (always existed, no starting point)  Plato (427-347 BC)  Everyone has innate knowledge in our subconscious given at birth,  We must re-remember what our soul learned in a past life  Souls’ experiences refine the forms it knows, “purifying” ideas through reincarnation  The Meno – dialogue between Plato and his teacher Socrates  Plato: “: Can you tell me, Socrates, is virtue acquired by teaching? Or not by teaching but by training? Or neither by training or learning but comes to men naturally or in some other way?”  Socrates: ”Thus the soul, since it is immortal and has been born many times, and has seen all things both here and in the other world, has learned everything that is, so we need not be surprised if it can recall the knowledge of virtue or anything else … for seeking and learning are nothing but recollection”  Socrates was able to teach a slave boy the Pythagorean theorem logical reasoning we use to figure out what happened  Plato (427-347 BC)  Similar to Gestalt psychologists (e.g. Max Wertheimer), which focuses on our innate tendencies towards “good form”  Trained a child with no mathematical training how to solve the altar window problem  Circular window, add tangent lines up to height of circle, then add semicircles, find the Find the area of space bounded outside of window area of these Take the semicircles and fit them into the regions “square” made from the tangent lines, so total area is equal to the square rationalist principles that underly psychological thought; that we go over the explanation for this don’t necessarily need experience to learn Confucius vs. Lao-tzu (~ 600 BC) Confucianism prioritize collective over individual, having structure in your life and how it relates to your community Focused on social and moral order, while not focusing on the larger “natural world”, more “directive” like some ie. be the forms of therapy best peasant you can be, People exist through the relationships of rather than trying to not others that are hierarchal structured be a peasant and be Social order is ensured by parties something higher honoring their social roles tumultuous time (drought, famine, wars, tribe invasions) -> need for stability and how to create that - everyone loses with a low ability to tolerate (used a word starting with a d) Confucius vs. Lao-tzu (~ 600 BC)  Taoism “Tao” – the way in which the Universe works Treated the natural and social order as connected and continuous  In Tao Te Ching – Lao-tzu talks about how any situation is always in the process of changing to the opposite  Can’t really be an ideal form or structure, since nature itself is constantly changing and evolving  More receptive appreciation of observation and reflection need for flexibility and adaptability to suit environment; fixating on one hierarchy/order will not help because you cannot change as your environment does  “I Ching” - The Book of Changes  Fortune telling device that codified possible future outcomes, using a binary system of yin (feminine, yielding, dark) and yang (masculine, firm, light)  “the power of tao to maintain the world through a constant renewal of a state of tension between the polar forces, is designated as good” fluctuations are predictable in someway, can be used to […..] for cyclical events  Was a way of representing cyclical change in the world that happens over time, using simple binary arithmetic to represent all situations  “I Ching” - The Book of Changes  Combining trigrams with 3 lines (2 options for each line, broken (yin) or solid (yang): 2 = 8 trigrams  Pairs of trigrams put together (including pairing the same trigram to itself) to form hexagram, all 8 = 64 combinations 64 conditions that cycle throughout the year  All broken lines (K’un- the Receptive) at bottom of circle  “the nature of the Earth, strong in devotion, represents late autumn in seasons, when forces of life is at rest” highest period of decline  All solid lines (Ch’ien – the Creative) at top of circle  “heaven, around May, time when growth and flowering is at peak highest period of growth Other Circumplex Models don’t need to know the emotion words in the circle, just where the 4 temperaments lie on the circle/grid  Galen’s typology of temperaments also related them to 4 fluids he thought existed within the body  Melancholic (black bile, pessimistic) – unchanging and emotional  Sanguine (blood, sociable) – changable and non-emotional  Choleric (bile, proud) – emotional and changeable  Phlegmatic (phelgm, controlled) – non- emotional and unchangeable  Other circumplex models include colour, facial expression, interpersonal characteristics and emotion  Aristotle (384-323 BC) - has rationalist principles, but appreciated empiricist perspective - must interact with the environment to understand, not just using logic to figure it out  Unlike Plato (his teacher), felt that form and matter were intertwined and could not exist without the other Typically accepted in Western culture go over this example today Benjamin Lee Whorf – reality composed of units defined by form + substance  E.g. quart of milk, kilogram of meat, snow crystal Click this link for more info: https://www.newworldencyclopedia.org/entry/Innate_idea  Aristotle (384-323 BC) similar to pythagorous’ unlimited and limited  Highlights differences between potentiality and actuality  A substance has the potential to take many forms, but only actual takes one at a time  E.g. a body has the potential to live if a soul inhabits it, will only actually live if a soul manifests itself in it  Ideas merely pre-existed potentially and needed to be actualized through experience an idea and understanding in the world requires experience to allow that concept to manifest as knowledge and incorporate it into the environment so it becomes something of substance Click this link for more info: https://www.newworldencyclopedia.org/entry/Innate_idea  Ended on this slide!! Aristotle (384-323 BC)  Hierarchy of living things reflected sophistication of one’s soul and their knowledge  Plants – power of “self-nutrition” - grows, continues to live if nourished  Animals – the power of sensation (humans have 5 senses – called “common sense”)  Humans – the power of reason  Reason (the mind) was indestructible  As you age and your body fails you, you still have the power of reason, even if the body makes it appear that you don’t bc it’s part of the soul, it cant be destroyed how does “cogito ergo sum” fit into this timeline wise? Starting here on May 15 both an empiricist (knowledge learnt from experience) and rationalist whereas plato is a rationalist Aristotle (384-323 BC) - not as subjective as others; found difficulty making it one bc it doesn’t exist in a vacuum and are subject to extra-scientific factors - perception of stumuli is subjective; can’t precisely always determine how/why and that interpretation needs to be taken into account  Humans can form a syllogism: consists of two premises and a conclusion logical inferences -> to figure out when something is or isn’t consistent  Example of how our behaviour is regulated by reason  Practical syllogism: the conclusion drawn from the two premises is an action  A) I have studied all topics of psychology (major premise) from the rule, can then determine whether the minor premises are “logical”  a statement of a general or universal nature , contains predicate of the conclusion  B) History of psychology is one of the topics in all of psychology (minor premise)  statement regarding a particular case, contains subject of the conclusion  C) History of psychology is something that I studied (conclusion) Subject: who or what is  inevitable result of accepting the major and minor premises performing the verb’s action  Syllogistic fallacy Predicate: everything that is there are rules of why it doesn’t make sense, but even if you don’t know the logical inference rules, not the subject it’s intuitive  A) I have studied all topics of psychology (major premise) Check this link for a more detailed explanation:  B) Calculus is a topic I have studied (minor premise) https://natureofwriting.com/courses/sentence- structure/lessons/finding-the-subject-  C) Calculus is one of all the topics in psychology (conclusion) 2/topic/finding-the-subject/ empiricism -> perfect forms - reduce something to a concept aside from your experience of it (to something characteristic) —> aristotle argues that isn’t possible (ie. if you think of milk, you think of the glass)  stimulus response reactions are limited; needed to account for mental representations later on Aristotle (384-323 BC) -> which is why cognitive psychology was developed  The Nature of Human Action  Human actions have a reason (i.e. a final cause) Actions: a particular set of movements that are guided teleologically (by goals/purposes) (e.g. opening a letter box) Motion: a set a movements with no order or reason behind them (i.e. falling off a cliff after being pushed) difference between actions we control and don’t - humans are different from animals because humans have more control, whereas animals are reacting to their environment  Aristotle (384-323 BC) became foundations for memory research in 1800s and 1900s and into today  Memory involves the reinstatement in consciousness of something which was there but had disappeared first to create fundamental rules through laws of associations that supported memory research  Laws of association: associations are produced by:  Similarity – reminded to the extent that something resembles what we are currently seeing (e.g. Plato and Aristotle are both Greek philosophers) these rules don’t happen in isolation; can overlap  Contrast – reminded to the extent that is means the opposite of what we are currently seeing (e.g. black and white)  Contiguity – reminded because it has been experienced together with whatever we are currently experiencing (e.g. fork and a kitchen) even if they’re not the same  Recollection is a mode of inference  One infers what one formerly experienced, and the process of inferring this experience is an investigation (more akin to imagination) than a literal rendition of the past so not re-experienced; it’s reconstructed: -> recalling (either bottom up or top down) means that we’ll fill in blanks -> best attempt to recreate; susceptible to having errors (especially for degraded memories aka over time)  Aristotle (384-323 BC) we learn best through visual information -> combining means you can strengthen memory  Mnemonic techniques- a device such as a pattern of letters, ideas, or associations that assists in remembering something (e.g. acronyms)  Used in ancient times to preserve history since printing had not been invented (oral traditions) especially important in oratory culture (and for orators); esp important bc people didn’t always sahare the same langage as those around them  “Ad Herennium”(~100 BC) studied by Frances Yates in The Art of Memory (1966)  Artificial memory – memory that can be developed through training to recall accurately many items  Aristotle (384-323 BC) DR MRS VANDERTRAMP uses this, i believe  Using imagery as a mnemonic tool:  2 parts – places (loci) and images to place in loci  Rules for loci  Loci must be learnt in a particular order that must be memorized  Loci must be a “deserted and solitary place”  Loci must be very different from each other  Loci should be at least 30 ft apart and bright  Every 5th locus is marked in a distinctive way  Rules of images  One image per item to be remembered job of orator would filter out people who had memory issues (like  Should be as distinctive and bizarre as aphantasia for example) possible - how does that fit into intelligence being class-dependent and also literacy rates and whos memory was better overtime with memory, those associations can be built and remembered - how does it fit in with life expectancy in years - would memory be better or worse Aristotle (384-323 BC)  Intelligence  Aristotle defined 3 kinds of intelligence  Theoretical intelligence: ability to understand subjects (e.g. math, science)  Practical intelligence: ability to choose a wise course of action decision making  Productive intelligence: ability to make certain things skills  Robert Sternberg proposed the triarchic theory of intelligence (1988) which mirrors Aristotle (analytical, creative, practical) and is derived from empirical methods Averroes (1126-98)  “The great Aristotelian of Islam” – wanted to show philosophical and religious thought were compatible  Aristotle’s theory of potentiality and actuality stated we all had the potential to be able to make extraordinary thoughts/achievements, but only some will actualize them averros argued…  We all have same intellectual potential, which is shaped by one’s active intellect which can make the potentially knowable known to use it, you have to actively engage w material and engage with your environmetn to develop it into something you can use St. Thomas Aquinas (1225-74)  Like Averroes wanted to show philosophical and religious thought (Christianity) were compatible  The “Scala Naturae” – the great chain of being constantly referred to in this time in Shakespeare  Built on hierarchy of living things from Aristotle  The universe is hierarchically arranged ordered “according to their internal perfection”, reflecting God’s purpose  Non-living things < Plants < Animals < Humans < Angels < God  Nothing in God’s plan is capricious, everything has a confucius in the east had a similar view with hierarches: needed purposeful order to maintain the role and fulfilll that role given in society  Consistent with the teachings of the Bible, which is irrefutable shouldn’t go against these teachings  Would be later challenged by Darwin and his theory of evolution no organism ahead of another; but each is adapted to its own environment and can change over time